CVE-2026-11623 tmux image.c image_free use after free
A use-after-free flaw in tmux allows local attackers to potentially execute arbitrary code or escalate privileges via complex exploitation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-11623?
CVE-2026-11623 is a low-severity use after free vulnerability in tmux, published on 9 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
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.
Which versions are affected by CVE-2026-11623?
Linux distribution packages (1)
tmux openSUSE:Tumbleweed | All versions | 3.6b-2.1 |
How do I fix CVE-2026-11623?
Upgrade to a fixed version.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-11623 being exploited?
There is no known exploitation of CVE-2026-11623 in the wild and no public exploit code.
Sources
Also known as AZL-90188, BELL-CVE-2026-11623, DEBIAN-CVE-2026-11623, ECHO-472d-c4a6-c1f9, GHSA-4cw9-jpqf-99x8, MGASA-2026-0255 and 3 more.