Transmission, the free open-source BitTorrent client for Linux, Windows, and macOS, released new 4.1.4 version a few days ago.
The new version is a bug-fix release that introduced various security and other small fixes.
Transmission 4.1.4 unified launch and delegation between the Qt and GTK clients. When either client is running, you won’t be able to launch the other client!
For example, when the Transmission GTK client is running, the Qt client won’t launch from the app launcher. If you try to open a torrent file with the Qt client, it will fall back to the already-running GTK client.
However, due to this change, Transmission GTK and Qt client installed either from source or native DEB package won’t launch in Ubuntu 26.04 and 26.10 due to AppArmor permission. See the “How to Install” section below to workaround.
Besides this change, it also fixed a potential RCE vulnerability in the macOS client.
And, it now protects against malformed RPC requests by validating torrent-priority arguments before processing them, preventing invalid indices from causing out-of-bounds memory access.
The Qt client has been improved to use less CPU. The GTK client’s torrent list now re-sorts and reapplies filters when a torrent’s name changes. And, the macOS client raised its minimum requirement to macOS 12.0.
Other changes are mostly bug-fixes. They include:
- Fix regression that could cause torrents with zero-byte files to be handled incorrectly.
- Migrate Sparkle update signing from DSA to EdDSA.
- Fix GTK client app icon not found on some desktops.
- Update zlib and Qt versions in Windows build.
- Fix web client display issue that sometimes listed torrent names as ‘Unknown’.
How to Install Transmission 4.1.4
More changes about the release, as well as the source tarball, Windows and macOS packages are available in Github via the link below:
For Linux, besides building from source or waiting for your distribution updates, user can also choose install the community maintained Flatpak package, which runs in sandbox.
There’s also snap package that’s available to install in Ubuntu App Center (or Ubuntu Software), which however is not updated at the moment of writing.
For Ubuntu 22.04, Ubuntu 24.04, Ubuntu 26.04 and 26.10, I’ve built the native DEB package into this PPA.
Simply press Ctrl+Alt+T to open terminal, and run commands below one by one to add PPA and install the package:
sudo add-apt-repository ppa:ubuntuhandbook1/transmission
sudo apt update
sudo apt install transmission
To fix the app launch issue in Ubuntu 26.04/26.10, open terminal and run command:
sudo nano /etc/apparmor.d/local/transmission
The command will open (create if does not exist) a local override for AppArmor’s Transmission profile. When file opens, paste the lines below:
# Allow Transmission GTK to lock its configuration files.
owner @{HOME}/.config/transmission/** k,
Then, press Ctrl+S to save and Ctrl+X to exit. It grants the owner (usually yourself) file-locking operations to files under .config/transmission directory, needed to prevent running GTK & Qt clients at the same time.
Finally, reload the AppArmor profile to apply change.
sudo apparmor_parser -r /etc/apparmor.d/transmission
