Vulnerability · Published Jun 9, 2026 · Assigned by VulDB
CVE-2026-11623tmux image.c image_free use after free
Medium 4.5
In plain English
A medium-severity use-after-free in tmux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
A security vulnerability has been detected in tmux up to 3.6a. Affected is the function image_free of the file image.c. Such manipulation leads to use after free. Local access is required to approach this attack. This attack is characterized by high complexity. The exploitability is told to be difficult. The exploit has been disclosed publicly and may be used. Upgrading to version 3.7-rc is able to address this issue. The name of the patch is fc6d94a9f8a593bd8b7031650802084385d4ee03. The affected component should be upgraded.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | tmux | 3.6b-1 | DEBIAN-CVE-2026-11623 |
| Ubuntu:26.04:LTS | tmux | 3.6a-2ubuntu0.1 | USN-8428-1 |
| Ubuntu:26.04:LTS | tmux | 3.6a-2ubuntu0.1 | UBUNTU-CVE-2026-11623 |
Affected products (as reported)
Weakness: CWE-416, CWE-119 · Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C
References
- VDB-369303 | tmux image.c image_free use after free vdb-entry, technical-description
- VDB-369303 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
- CVE-2026-11623 | CVE Analysis and Report third-party-advisory
- Submit #835623 | tmux <= 3.6a Use After Free third-party-advisory
- https://gist.github.com/XlabAITeam/f0d9952595f795129a3258ba73bbc3cb exploit
- https://github.com/tmux/tmux/commit/fc6d94a9f8a593bd8b7031650802084385d4ee03 patch
- https://github.com/tmux/tmux/releases/tag/3.7-rc patch
- https://github.com/tmux/tmux/ product