==========================================================================
Ubuntu Security Notice USN-8404-1
June 08, 2026

transmission vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 26.04 LTS
- Ubuntu 25.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS

Summary:

Transmission could allow unintended actions if a user visited a malicious
website.

Software Description:
- transmission: lightweight BitTorrent client

Details:

It was discovered that Transmission had a clickjacking weakness in the
browser-facing WebUI and RPC response paths. An attacker could possibly use
this issue to trick users into performing unintended actions.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 26.04 LTS
  transmission                    4.1.1+dfsg-1ubuntu1.1
  transmission-daemon             4.1.1+dfsg-1ubuntu1.1

Ubuntu 25.10
  transmission                    4.1.0~beta2+dfsg-3ubuntu1.1
  transmission-daemon             4.1.0~beta2+dfsg-3ubuntu1.1

Ubuntu 24.04 LTS
  transmission                    4.0.5-1ubuntu0.1
  transmission-daemon             4.0.5-1ubuntu0.1

Ubuntu 22.04 LTS
  transmission                    3.00-2ubuntu2.2
  transmission-daemon             3.00-2ubuntu2.2

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-8404-1
  CVE-2026-38978

Package Information:
  https://launchpad.net/ubuntu/+source/transmission/4.1.1+dfsg-1ubuntu1.1
  https://launchpad.net/ubuntu/+source/transmission/4.1.0~beta2+dfsg-3ubuntu1.1
  https://launchpad.net/ubuntu/+source/transmission/4.0.5-1ubuntu0.1
  https://launchpad.net/ubuntu/+source/transmission/3.00-2ubuntu2.2