Security teams staring at a commercial SIEM renewal invoice have three open-source names coming up in almost every forum thread this month: Wazuh, Security Onion, and CrowdSec. None of them do exactly the same job, and that is the part most “best free SIEM” roundups skip. Wazuh is a combined XDR and SIEM platform built around an agent on every endpoint. Security Onion is a full network-security-monitoring distribution built for packet capture and threat hunting. CrowdSec is a collaborative intrusion-prevention engine that leans on shared IP-reputation data rather than log correlation. Picking the wrong one for your use case means re-architecting your detection stack a year later.
The timing makes the comparison more than academic. Ransomware showed up in 48% of breaches analyzed in Verizon’s 2026 Data Breach Investigations Report, up from 44% a year earlier, even as the share of victims who actually pay keeps falling (69% did not pay, and the median ransom dropped to $139,875). Exploitation of unpatched vulnerabilities has now overtaken stolen credentials as the single most common way breaches start, according to breach-statistics research compiled by Secureframe, which also counted 1,803 US data compromises in just the first half of 2026. Microsoft’s October 2026 Patch Tuesday addressed at least 1,413 vulnerabilities, blowing past September’s then-record 974, per SANS NewsBites. Every one of those numbers is a reason security teams are looking hard at what they are running for detection and prevention, and whether they can afford to keep paying for it.
This comparison walks through the current state of Wazuh (version 4.14.9), Security Onion (version 3.3.0), and CrowdSec (version 1.8) as of October 20, 2026: what each one actually does, what it costs once you move past the free tier, how the three stack up on a feature-by-feature basis, and which one fits which kind of team. Wazuh 5.0.0 exists only as a release candidate at the time of writing and is not yet the shipping version, so every comparison below uses the 4.14.9 stable line unless noted otherwise.
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What Is Wazuh? Open-Source XDR and SIEM in One Agent
Wazuh describes itself as a free and open-source security platform that combines XDR (extended detection and response) and SIEM (security information and event management) capabilities across endpoints and cloud workloads. The architecture is built from four pieces: the Wazuh manager, which receives and correlates events; the Wazuh agent, installed on each monitored host; the Wazuh indexer, which stores and indexes the resulting data; and the Wazuh dashboard, the web interface analysts actually use. There is no separate license fee for any of those four components, which is the core of Wazuh’s pitch against commercial SIEM vendors that charge per gigabyte ingested or per agent deployed.
The current stable release is Wazuh 4.14.9, published on October 14, 2026. It is a cumulative update, meaning it rolls in everything from 4.14.8 and 4.14.7 plus its own fixes. The 4.14.9 changelog is mostly hardening and reliability work rather than headline features: compiler-hardening improvements, tighter privacy controls on API access logs, an upgraded embedded Python 3.10.21 runtime with dependency bumps for cryptography and pip, expanded eBPF file-integrity-monitoring (FIM) compatibility for older kernels (including whodata support on kernels older than 5.8, which covers RHEL 8.10), and a fix for a Windows active-response bug that broke the netsh and route-null responses because IP validation called getaddrinfo() without initializing Winsock first.
That kind of patch cadence (three cumulative point releases in under three months) says something about where Wazuh is putting its engineering effort right now: Security Configuration Assessment (SCA) accuracy, eBPF-based FIM coverage, and active-response reliability, rather than a ground-up rewrite. The actual rewrite is Wazuh 5.0.0, which exists today only as a release candidate (5.0.0-rc1, which appeared October 5, 2026) inside Wazuh’s own documentation. It is explicitly marked as under development. Teams evaluating Wazuh in late 2026 should plan around the 4.14.x line for production and treat 5.0 as a preview to watch, not something to deploy yet.
Wazuh has also been expanding through channel partnerships rather than big-bang feature launches: an August 12, 2026 partnership with Clober (SATEC Group’s cloud and cybersecurity brand), a September 28 partnership with AI Cyber Consulting aimed at strengthening SOC services, an October 2 partnership with Cyber Guard Pro focused on security visibility, and an October 7 partnership described as improving digital environments. None of those publicly disclose pricing, but they point at Wazuh positioning itself as the detection layer inside managed security service provider (MSSP) stacks, not just a DIY tool for solo security engineers.
What Is Security Onion? Network Security Monitoring, Not Just Logs
Security Onion started life in 2008 when Doug Burks began building a Linux distribution focused on intrusion detection, network security monitoring, and log management. That network-first lineage is still the main thing separating it from Wazuh: where Wazuh centers on an agent sitting on each endpoint, Security Onion centers on full packet capture and network traffic analysis, with host-based telemetry layered on top rather than being the primary data source.
The free distribution is simply called Security Onion; the commercial layer on top is Security Onion Pro, sold by Security Onion Solutions. Security Onion 3 is the current major line, requiring Oracle Linux 9, and it fully replaced the older 2.4 branch, which reached its announced end-of-life on October 1, 2026 after a six-month EOL notice posted back in April. Anyone still running 2.4 on an unsupported distribution now needs a fresh Security Onion 3 installation rather than an in-place upgrade.
Inside the 3.x line, the release cadence has been fast. Security Onion 3.2.0 shipped in July 2026 and introduced the platform’s first agentic-AI framework along with Gemma 4 31B as a selectable local Onion AI model. Security Onion 3.3.0 then shipped September 8, 2026 (with a 3.3.0-20260911 hotfix build following on September 11) and added Agent Studio, agentic memory, Manager-of-Managers subgrid roles for multi-site deployments, and Onion AI Reports. That is a meaningfully different trajectory than Wazuh’s recent releases: Security Onion is actively building out AI-assisted triage and reporting as a core differentiator, while Wazuh’s recent point releases have stayed focused on detection-accuracy fixes.
Security Onion Pro is the part that is not free. Its documented feature list includes Active Query Management, external API access, OIDC single sign-on, data-at-rest encryption, FIPS and DoD STIG compliance options, external notifications, guaranteed message delivery, Manager of Managers, an MCP Server, Splunk integration, a management Hypervisor, enhanced Reports, and the Onion AI Assistant. Security Onion Solutions also sells quote-based hardware appliances under names including SN7200, SNNV, and GoFast for organizations that want a turnkey sensor rather than building their own. None of that is priced publicly; the official line is to contact Security Onion Solutions directly, which matters if your procurement process needs a number before it can even start evaluating a vendor. The company runs an annual user conference, with the 12th Security Onion Conference scheduled for Augusta, Georgia on October 23, 2026, alongside the broader Augusta Cyber Week running October 19–24.
What Is CrowdSec? Collaborative Intrusion Prevention, Not a Traditional SIEM
CrowdSec is the odd one out in this comparison, and it is worth being precise about why before putting it in a head-to-head table with Wazuh and Security Onion. CrowdSec’s own documented stack is built around the CrowdSec Security Engine (an open-source collaborative intrusion detection system), a Web Application Firewall (WAF) component, and an AppSec module that includes a bot-detection feature. Its core value proposition is not deep log correlation across every system in your environment; it is automated blocking driven by crowd-sourced IP-reputation intelligence, where signals detected by one CrowdSec deployment get shared (anonymized) back to the community and used to protect everyone else running the engine.
The current stable release is CrowdSec 1.8, announced September 1, 2026, which added WAF bot detection, a dedicated Kubernetes data source, faster LAPI (Local API) synchronization, and general performance improvements. CrowdSec is explicit that bot detection remains an alpha feature as of its most recent documentation updates in mid-October 2026, so it is a real capability but not one CrowdSec itself calls production-mature. The prior notable release, 1.7.8, was a security patch addressing two vulnerabilities: CVE-2026-44982, a high-severity WAF bypass, and CVE-2026-44981, a Local API denial-of-service issue.
CrowdSec’s pricing structure also looks different from the other two because it is built around a freemium threat-intelligence business, not just an open-core SIEM. The free Community plan covers individuals and small deployments. Above that sits an Enterprise plan billed as pay-as-you-grow, scaled primarily by the number of enrolled Security Engines rather than data volume. CrowdSec also sells IP Reputation and CTI (cyber threat intelligence) access starting at $49 per month for 5,000 API queries, with a free CTI API key offering 120 lookups per month for teams testing SIEM integrations. On top of that sit Platinum Blocklists starting at $1,900 per month for SMB access to the full blocklist catalog on any number of company endpoints, optional premium support at $1,000 per month per enrolled Security Engine, emergency bug-fix service also at $1,000 per month, and local CTI replication starting at $9,000 per month for teams that need the threat feed mirrored inside their own infrastructure rather than queried over the internet. CrowdSec’s own published commentary from mid-October 2026 acknowledges that pricing strategy has been a live point of community debate, which is worth knowing before you build a budget around it.
Wazuh vs Security Onion vs CrowdSec: Specs Comparison
Here is how the three platforms line up on architecture, licensing, and capability as of October 20, 2026.
| Category | Wazuh | Security Onion | CrowdSec |
|---|---|---|---|
| Primary function | Open-source XDR + SIEM | Network security monitoring + threat hunting | Collaborative intrusion prevention / CTI |
| Current stable version | 4.14.9 (October 14, 2026) | 3.3.0 (September 8, 2026) | 1.8 (September 1, 2026) |
| Next-gen version status | 5.0.0-rc1 (release candidate, October 5, 2026; not yet stable) | No confirmed successor line announced | No confirmed successor line announced |
| Core architecture | Manager, agent, indexer, dashboard | Sensor, search node, manager grid (Manager-of-Managers) | Security Engine, WAF module, AppSec/bot detection, LAPI, Console |
| Primary data source | Endpoint/host agent logs, FIM, eBPF telemetry | Full packet capture, network traffic metadata | Web server/app logs, firewall/WAF signals, shared IP reputation |
| Deployment model | Self-hosted; manager + distributed agents | Self-hosted appliance/grid; Oracle Linux 9 required for v3 | Self-hosted engine; cloud-hosted Console/CTI layer |
| License for core product | Free and open source | Free and open source (core distribution) | Free (Community plan) |
| Paid tier name | No official SaaS tier publicly priced | Security Onion Pro (quote-based) | Enterprise, Console Premium, CTI, Platinum Blocklists |
| AI/automation features | None specifically marketed as of 4.14.9; partnerships with AI-focused MSSPs | Onion AI Assistant, Agent Studio, agentic memory, Gemma 4 31B model option | WAF bot detection (alpha, added in 1.8) |
| Multi-site management | Multiple managers possible; no dedicated MoM branding | Manager-of-Managers subgrid roles (added 3.3.0) | Central Console across multiple Security Engines |
| Compliance mappings | Documented HIPAA control mappings (e.g., §164.308, §164.312) | FIPS and DoD STIG options in Pro tier | Not positioned as a compliance-mapping tool |
| Hardware appliance option | Not offered directly | Yes: SN7200, SNNV, GoFast (quote-based) | Not offered |
| Best known for | Endpoint FIM, log correlation, SCA policy checks | Full-packet threat hunting, network forensics | Automated IP blocking, bot/scraper mitigation, shared CTI |
Benchmarks and Published Performance Data
Direct, apples-to-apples benchmark numbers across all three tools do not exist, mostly because they are not solving an identical problem. What does exist is a set of vendor-published and case-study figures that are worth laying out, with the caveat that CrowdSec’s numbers come from its own marketing and case-study material rather than an independent lab, and neither Wazuh nor Security Onion currently publishes comparable quantitative detection-rate claims.
CrowdSec says its shared blocklists can stop up to 95% of mass exploitation attempts before they reach a protected system, and that its high-threat CTI list contains 36% exclusive data not found in other threat-intelligence sources. In one published case study, a CrowdSec customer reported eliminating between 40% and 50% of security alert background noise, which the customer said freed up roughly two full-time-equivalent staff worth of incident-response time while reducing CPU and RAM load on their servers. A separate case study involving the CrowdSec WAF and bot-detection module against a large-scale scraping operation reported blocking approximately 95% of malicious bot traffic while improving performance for legitimate users. In September 2026, CrowdSec’s bot-detection feature, still labeled alpha, was credited with helping identify what the company called the “PaperPhone” cluster: a bot network CrowdSec’s own blog post title puts at more than 75,000 IP addresses, with body text describing it as roughly 80,000 IPs spread across 43 countries.
Those numbers sit inside a bigger exploitation trend that makes any automated-blocking layer look more attractive right now. CrowdSec’s own research, covering data from 500,000 servers, found that 36% of exploited CVEs were attacked within a day of publication, pointing to a faster and more automated exploitation cycle. That tracks with what CrowdSec’s own vulnerability-tracking team has been publishing: an October 19, 2026 report on CVE-2026-88771, a Citrix NetScaler command-injection flaw being actively exploited, and an October 5, 2026 report on CVE-2026-85706, a critical GitLab unauthenticated file-read vulnerability also seen exploited in the wild. Neither Wazuh nor Security Onion publishes an equivalent public threat-tracking feed of named CVEs, which is a real differentiator if your team wants a vendor actively publishing exploit intelligence rather than just a detection engine you have to feed yourself.
| Published metric | Platform | Figure | Context |
|---|---|---|---|
| Mass-exploitation block rate (vendor claim) | CrowdSec | Up to 95% | Shared blocklist/CTI protection |
| CTI data exclusivity (vendor claim) | CrowdSec | 36% | vs. other threat-intel sources |
| Alert noise reduction (case study) | CrowdSec | 40%–50% | One enterprise customer, background-noise filtering |
| Bot-traffic block rate (case study) | CrowdSec | ~95% | WAF + bot detection vs. scraping attack |
| Bot network scale uncovered | CrowdSec | 75,000+ IPs, 43 countries | “PaperPhone” cluster, alpha bot detection |
| Ransomware share of breaches | Industry baseline | 48% | Verizon 2026 DBIR, up from 44% |
| October 2026 Patch Tuesday volume | Industry baseline | 1,413 CVEs | SANS NewsBites, record over September’s 974 |
Pricing Breakdown: What Actually Costs Money
All three platforms lead with a free, self-hosted core, but the point where money starts changing hands looks very different across them.
Wazuh’s core platform (manager, agent, indexer, dashboard) carries no license fee, and Wazuh has not published an official hosted or managed-service price list. Some third-party resellers reportedly advertise managed Wazuh tiers, including a “Small” plan cited around $571 per month for up to 100 agents, but that figure comes from a reseller reference point rather than Wazuh’s own pricing page, so treat it as directional rather than official. If your organization wants Wazuh with vendor support, budget for either an MSSP partnership (several of which Wazuh has announced through 2026) or self-managed infrastructure costs, not a published subscription fee.
Security Onion follows the classic open-core model: the distribution itself is free, and Security Onion Pro is quote-based, with the vendor directing prospective buyers to contact Security Onion Solutions directly rather than publishing tiered pricing. Hardware appliances (SN7200, SNNV, GoFast) are also quote-based. That makes Security Onion the hardest of the three to budget for without a sales conversation, but it also means pricing can flex to deployment size in a way a fixed public price sheet cannot.
CrowdSec publishes the most granular public price list of the three, which is unusual for an open-source security tool and worth calling out as a genuine differentiator either way you want to read it.
| Platform | Tier | Price | What you get |
|---|---|---|---|
| Wazuh | Core platform | Free | Manager, agent, indexer, dashboard, self-hosted |
| Wazuh | Managed/reseller tier (third-party, unofficial) | ~$571/month (reported) | Up to 100 agents, not an official Wazuh price |
| Security Onion | Core distribution | Free | Full network monitoring stack, self-managed |
| Security Onion | Security Onion Pro | Contact sales (quote-based) | OIDC, FIPS/STIG, Manager of Managers, Onion AI Assistant |
| Security Onion | Hardware appliances | Contact sales (quote-based) | SN7200, SNNV, GoFast sensors |
| CrowdSec | Community | Free | Core Security Engine, individual/small deployments |
| CrowdSec | CTI / IP Reputation API | From $49/month | 5,000 API queries/month (free tier: 120 lookups/month) |
| CrowdSec | Platinum Blocklists | From $1,900/month | SMB access to full blocklist catalog, unlimited endpoints |
| CrowdSec | Premium support | $1,000/month per Security Engine | Priority support per enrolled engine |
| CrowdSec | Emergency bug fixes | $1,000/month | Expedited patch service |
| CrowdSec | Local CTI replication | From $9,000/month | Threat feed mirrored inside customer infrastructure |
| CrowdSec | Enterprise | Pay-as-you-grow (custom) | Priced by number of enrolled Security Engines |
Architecture Deep Dive: How Each Platform Actually Collects Data
Wazuh’s data pipeline starts at the agent. Each monitored endpoint runs a lightweight agent that performs file-integrity monitoring (including eBPF-based whodata collection on supported kernels), log collection, rootkit detection, and Security Configuration Assessment checks against policy baselines (CIS benchmarks and similar). The agent ships events to the Wazuh manager, which applies correlation rules and decoders, triggers active responses (like the Windows netsh/route-null blocking that got a bug fix in 4.14.9), and forwards normalized data to the Wazuh indexer for storage and search. Analysts work through the Wazuh dashboard. The practical implication: Wazuh’s visibility is as good as its agent coverage. Any host without an agent installed is a blind spot, which is the same tradeoff every EDR-style agent architecture makes.
Security Onion flips that model. Sensors capture full packets and derive network metadata (via tools like Zeek and Suricata under the hood, standard to the Security Onion distribution), which gets indexed and made searchable across a grid of search nodes managed through a central manager, with the newer Manager-of-Managers subgrid role letting large deployments split across multiple management points. This means Security Onion sees everything that crosses the wire, including devices you cannot install an agent on, but it needs network tap or span-port access, and it deals with encrypted traffic the way any packet-capture tool does: metadata and behavioral analysis rather than full content inspection once TLS is involved, unless you are doing TLS interception separately.
CrowdSec’s architecture is the most different of the three. The Security Engine ingests logs (web server, firewall, application) locally, parses them against community-maintained detection scenarios, and when it identifies malicious behavior, it can trigger a local block (via a “bouncer” component) and optionally report the offending IP back to the CrowdSec community CTI network, anonymized. That shared-intelligence loop is the entire value proposition: your Security Engine benefits from attacks seen by every other CrowdSec deployment globally, not just your own traffic. The WAF and AppSec/bot-detection modules, introduced incrementally through 2026 and expanded in version 1.8 with a dedicated Kubernetes data source, extend that same detection model into application-layer and container-native traffic. It is architecturally closer to a modern, crowd-sourced intrusion-prevention system than to a SIEM that retains and lets you query historical logs the way Wazuh or Security Onion do.
# Example: typical CrowdSec Security Engine + bouncer flow (illustrative, not official syntax)
# 1. Security Engine parses local logs against community scenarios
cscli scenarios list
# 2. A matching scenario triggers a decision (ban, captcha, etc.)
cscli decisions list
# 3. A bouncer (e.g., the nginx or firewall bouncer) enforces the decision
cscli bouncers list
# 4. Optionally, the anonymized signal is shared back to the CrowdSec CTI network
cscli console enroll <enroll-key>AI and Automation Features Compared
This is the sharpest point of divergence among the three right now. Security Onion has moved the fastest and the most publicly on AI. Its 3.2.0 release (July 29, 2026) introduced an initial agentic-AI framework and added Gemma 4 31B as a locally runnable Onion AI model option, letting teams keep AI-assisted analysis inside their own infrastructure rather than calling out to a third-party API. Six weeks later, 3.3.0 (September 8, 2026) built on that with Agent Studio for constructing custom AI agents, agentic memory so those agents retain context across sessions, and Onion AI Reports for automated report generation. The most advanced capability, the Onion AI Assistant, sits in the paid Security Onion Pro tier rather than the free distribution, which is worth knowing before assuming “Security Onion has AI” means “the free version has AI.”
CrowdSec’s AI-adjacent capability is narrower but more production-relevant for a specific problem: distinguishing human traffic from bots. The bot-detection feature, added in version 1.8 (September 1, 2026), uses behavioral signals to flag automated traffic hitting the WAF, and it was credited in case-study material with helping surface the PaperPhone bot cluster. CrowdSec is explicit, as of its October 2026 documentation, that bot detection is still an alpha feature, meaning it should be evaluated and piloted rather than treated as a finished, universally reliable capability.
Wazuh, by contrast, has not shipped a comparable AI feature inside the core 4.14.x product as of this writing. Its recent momentum in the AI space is indirect, through partnerships like the September 28, 2026 agreement with AI Cyber Consulting aimed at strengthening SOC services, which suggests Wazuh is leaving AI-assisted triage to ecosystem partners rather than building it natively, at least until the 5.0 line matures past release-candidate status. Teams that specifically want AI-assisted alert triage inside the platform itself should weight that difference heavily, since it is the single biggest capability gap between Wazuh and Security Onion right now.
Real-World Deployment Examples
Five patterns show up repeatedly in how organizations are actually using these three tools in 2026, plus a sixth that combines them.
- Regulated healthcare environments running Wazuh for compliance evidence. Wazuh ships documented control mappings against HIPAA requirements, including §164.308(a)(1)(ii)(A) (risk analysis), §164.308(a)(5)(ii)(B) (protection from malicious software), §164.308(a)(6)(ii) (response and reporting), §164.308(a)(8) (evaluation), and §164.312(a)(2)(iii) (automatic logoff). Its file-integrity monitoring and Security Configuration Assessment checks give compliance teams a direct audit trail without paying per-agent SIEM licensing on every clinical workstation.
- MSSPs building managed detection services on top of Wazuh’s partner ecosystem. Wazuh’s 2026 partnerships with firms like Cyber Guard Pro, AI Cyber Consulting, and Clober (SATEC Group’s cybersecurity brand) point to a pattern where service providers use Wazuh as the underlying detection engine and sell the monitoring and response layer on top, rather than organizations self-managing it end to end.
- University and enterprise network-security teams running Security Onion for full-packet threat hunting. Security Onion’s network-first design, plus its active community (visible in events like the 12th annual Security Onion Conference in Augusta, Georgia on October 23, 2026, part of the broader Augusta Cyber Week) makes it a common choice for teams whose primary job is investigating lateral movement and command-and-control traffic rather than endpoint compliance.
- Web platforms using CrowdSec’s WAF and bot detection against large-scale scraping and credential-stuffing traffic. A CrowdSec case study describes deploying the Security Engine alongside the WAF and bot-detection module against a large scraping operation, reporting roughly 95% of malicious bot traffic blocked while improving legitimate-user performance; a separate nginx-focused case study follows the same pattern against generic bot abuse.
- Security teams using CrowdSec’s CTI feed to track actively exploited CVEs. CrowdSec’s own vulnerability-tracking reports, including its October 19, 2026 writeup on the actively exploited Citrix NetScaler command-injection flaw (CVE-2026-88771) and its October 5, 2026 report on the critical GitLab file-read vulnerability (CVE-2026-85706), function as a lightweight threat-intel feed that teams fold into patch-prioritization decisions alongside Platinum Blocklist subscriptions.
- Layered stacks that run all three together. Because Wazuh, Security Onion, and CrowdSec cover endpoint, network, and perimeter/edge respectively, some security teams run them in combination: Wazuh agents on hosts for FIM and compliance logging, Security Onion sensors on key network segments for packet-level visibility, and CrowdSec bouncers on internet-facing services for automated IP blocking, feeding shared signals into whichever platform does log retention for the organization.
Migration Guide: Moving From a Commercial SIEM to an Open-Source Stack
Replacing a commercial SIEM with any combination of these three tools is a project, not a weekend swap. Here is a realistic sequence.
- Inventory your current log sources and retention requirements first. Before picking a replacement, document every data source your commercial SIEM ingests today and how long you are contractually or legally required to retain it, since compliance mappings (like Wazuh’s HIPAA controls) only help if you know what you actually need covered.
- Decide whether your gap is endpoint, network, or perimeter visibility. If most of your current detections come from endpoint logs and file integrity checks, Wazuh is the closer architectural match. If most come from network traffic analysis, Security Onion is closer. If most come from blocking malicious IPs and bot traffic at the edge, CrowdSec is closer. Many teams need more than one.
- Stand up a parallel pilot environment, not a cutover. Deploy Wazuh managers/agents, a Security Onion sensor, or a CrowdSec Security Engine alongside your existing SIEM, pointed at a subset of production log sources, before touching anything your SOC currently depends on.
- Re-implement your highest-value detection rules first. Pull your current SIEM’s top 20–30 alert rules by volume and criticality, and rebuild the equivalent logic using Wazuh decoders/rules, Security Onion’s Suricata/Zeek-based detections, or CrowdSec scenarios, whichever platform you are migrating that detection to.
- Validate detection coverage with known-bad test traffic before trusting it. Run controlled test attacks (brute force, known malware signatures, port scans) against the pilot environment and confirm it actually fires the equivalent alert before retiring any coverage on the old system.
- Plan agent/sensor rollout in waves, not all at once. For Wazuh, roll agents out by business unit or environment tier; for Security Onion, bring sensors online segment by segment; for CrowdSec, enroll bouncers on lower-risk services before internet-facing production traffic.
- Run both systems in parallel for a full reporting cycle. Keep the legacy SIEM live until you have completed at least one full compliance or audit reporting cycle on the new stack, so you catch gaps before they become an audit finding.
- Budget for the paid layers you will actually need, not just the free core. Factor in Security Onion Pro (quote-based) if you need FIPS/STIG or OIDC, CrowdSec’s CTI and Platinum Blocklist tiers if you need broader threat intelligence than the free tier provides, and any Wazuh MSSP partnership costs if you need managed support rather than fully self-managing.
- Decommission the commercial SIEM only after a documented sign-off. Get formal sign-off from compliance, security leadership, and whoever owns audit response before turning off the legacy platform, since re-enabling a decommissioned commercial SIEM mid-incident is far worse than a slow migration.
Wazuh Pros and Cons
Wazuh’s biggest strength is breadth for zero license cost: FIM, log collection, SCA policy checks, and active response all live in one free agent-based platform, with documented compliance mappings that save real audit-prep time. The patch cadence (three cumulative releases since July 2026) shows active maintenance. The downsides: no native AI-assisted triage in the current stable line, no official public pricing for managed or hosted support (forcing teams into either full self-management or a partner relationship), and the upcoming 5.0 rewrite is still only a release candidate, so anyone evaluating Wazuh today is evaluating the 4.14.x architecture, not whatever 5.0 eventually becomes.
Security Onion Pros and Cons
Security Onion’s strength is depth of network visibility combined with the fastest-moving AI roadmap of the three: agentic AI, Agent Studio, and a locally runnable Gemma 4 31B model option, all shipped within a single quarter (3.2.0 in July, 3.3.0 in September 2026). It also has the most mature commercial support option, including FIPS/DoD STIG compliance and hardware appliances, for organizations that need vendor accountability. The downsides: no public pricing for Security Onion Pro or hardware, meaning budget approval requires a sales conversation before you can even scope the project; the most advanced AI feature (the Onion AI Assistant) is gated behind that same paid tier; and the mandatory move to Oracle Linux 9 for Security Onion 3 is a real migration cost for anyone still on 2.4, especially now that 2.4 is past its October 1, 2026 end-of-life date.
CrowdSec Pros and Cons
CrowdSec’s strength is the one thing neither Wazuh nor Security Onion really does: collaborative, shared threat intelligence that gets better as more organizations run it, backed by the most transparent public pricing of the three vendors. Its published vulnerability-tracking reports (covering actively exploited CVEs like the Citrix NetScaler and GitLab flaws) also give it a visible research arm that functions as a lightweight CTI feed. The downsides: it is not a full SIEM, so teams expecting long-term log retention and complex correlation out of the box will be disappointed; bot detection, its most AI-adjacent capability, is still labeled alpha; and the tiered pricing (CTI from $49/month, Platinum Blocklists from $1,900/month, local CTI replication from $9,000/month) adds up quickly for organizations that want full coverage rather than the free Community tier, and CrowdSec’s own commentary acknowledges pricing has been a point of community pushback.
Which One Should You Choose? Use-Case Recommendations
- Compliance-driven organizations (healthcare, finance) needing endpoint audit evidence: Wazuh, for its documented HIPAA control mappings and zero-cost FIM/SCA coverage across every host.
- Teams whose core job is network-level threat hunting and incident investigation: Security Onion, for full packet capture and the fastest-growing AI-assisted analysis toolset among the three.
- Public-facing websites and APIs fighting scrapers, bots, and mass exploitation attempts: CrowdSec, for its WAF, bot detection, and shared-blocklist model built specifically for perimeter automated abuse.
- Budget-constrained startups and small teams: Wazuh’s core platform or CrowdSec’s Community plan, since both offer meaningful protection at zero license cost before any paid tier becomes necessary.
- MSSPs and organizations that want vendor-backed support with compliance certifications: Security Onion Pro, for its FIPS and DoD STIG options and quote-based hardware appliances aimed at buyers who need a vendor relationship, not just software.
- Kubernetes-native application teams: CrowdSec, given the dedicated Kubernetes data source added in version 1.8.
- Mature security programs with dedicated engineering capacity: a layered combination of all three, using each for the layer it is architecturally built for (endpoint, network, perimeter) rather than forcing one tool to cover every layer.
The Verdict: Scoring Wazuh, Security Onion, and CrowdSec
There is no single winner here because the three tools are not competing for the same job, and pretending otherwise would be the kind of oversimplification this comparison set out to avoid. If the question is “which free, open-source SIEM/XDR should replace my endpoint-focused commercial tool,” the answer is Wazuh, on the strength of its HIPAA-mapped compliance coverage, its zero-cost four-component architecture, and a release cadence (4.14.7 through 4.14.9 since July 2026) that shows active maintenance even without flashy new features. If the question is “which tool should sit on my network and do the deep forensic work,” it is Security Onion, which has pulled ahead on AI-assisted analysis with agentic workflows and a locally runnable Gemma 4 31B model, at the cost of needing a sales conversation for anything beyond the free distribution. If the question is “what stops bots, scrapers, and mass exploitation attempts at my edge before they ever reach a log,” it is CrowdSec, whose published numbers (up to 95% block rates on both mass exploitation and bot traffic in case studies, 36% exclusive CTI data) are the most quantified of the three, backed by the most transparent, if also the priciest-at-scale, public pricing.
Given how fast the threat landscape these tools defend against is moving (48% ransomware breach rate, 1,413 vulnerabilities in a single Patch Tuesday, exploitation now outpacing stolen credentials as the top breach vector) the more defensible answer for most mid-size and larger security teams is not “pick one” but “pick the right one for each layer, starting with whichever gap hurts the most today.” Teams with nothing in place should start with Wazuh for the broadest free coverage, add CrowdSec quickly for perimeter protection given how cheap its entry CTI tier is relative to the exposure it addresses, and evaluate Security Onion once network-level visibility becomes the clear remaining gap.
Frequently Asked Questions
Is Wazuh really free, or are there hidden costs?
The core Wazuh platform (manager, agent, indexer, dashboard) is free and open source with no license fee. Costs come from infrastructure (servers to run the manager/indexer), staff time to manage it, and optional MSSP or support-partner relationships, since Wazuh does not publish an official hosted pricing tier as of October 2026.
Can I run Wazuh, Security Onion, and CrowdSec together?
Yes, and some organizations do, since they cover different layers: Wazuh on endpoints, Security Onion on the network, and CrowdSec at the perimeter. They are not mutually exclusive and do not directly compete for the same data source.
Should I wait for Wazuh 5.0 instead of deploying 4.14.9 now?
No. Wazuh 5.0 exists only as a release candidate (5.0.0-rc1, from October 5, 2026) and is explicitly marked as under development. Production deployments should use the 4.14.x stable line; 5.0 is worth watching but not yet something to build a production environment on.
Do I need to upgrade from Security Onion 2.4?
Yes, if you have not already. Security Onion 2.4 reached its announced end-of-life on October 1, 2026, and Security Onion 3 requires a fresh installation on Oracle Linux 9 rather than an in-place upgrade from an unsupported distribution.
Is CrowdSec’s bot detection reliable enough for production?
CrowdSec itself labels bot detection, added in version 1.8, as an alpha feature as of its October 2026 documentation. It has been used successfully in case studies, including identifying the “PaperPhone” bot cluster, but it should be piloted rather than assumed production-ready without validation in your own environment.
Which tool is best for a small team with no dedicated security engineer?
CrowdSec’s Community plan or Wazuh’s core platform both offer meaningful protection without requiring a large team, since CrowdSec’s model relies partly on crowd-sourced intelligence rather than requiring you to write detection rules from scratch, and Wazuh ships with pre-built SCA policies and compliance mappings out of the box.
How does CrowdSec’s pricing compare at scale?
CrowdSec’s entry CTI tier starts at $49/month for 5,000 API queries, but costs climb quickly for larger deployments: Platinum Blocklists start at $1,900/month, premium support is $1,000/month per Security Engine, and local CTI replication starts at $9,000/month. Teams should model their expected scale against these tiers before committing, since CrowdSec’s own commentary has acknowledged pricing has drawn community criticism.
Does any of these three tools map directly to compliance frameworks like HIPAA or PCI DSS?
Wazuh is the only one of the three with documented, specific compliance control mappings, including HIPAA sections such as §164.308(a)(1)(ii)(A) and §164.312(a)(2)(iii). Security Onion offers FIPS and DoD STIG options, but only inside the paid Security Onion Pro tier. CrowdSec is not positioned as a compliance-mapping tool at all.
