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 products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | tmux | 3.6a | 3.7-rc |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | tmux | 3.6b-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | tmux | 3.6a-2ubuntu0.1 | USN-8428-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | tmux | 3.6b-2.1 | openSUSE-SU-2026:11006-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | tmux | 3.4-2 | — |
Advisories 2
- USN-8428-1 tmux vulnerability Ubuntu Security Notices (USN) · Jun 15, 2026
- openSUSE-SU-2026:11006-1 tmux-3.6b-2.1 on GA media SUSE / openSUSE Security Updates · Jun 12, 2026
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