CVE-2026-11623

NameCVE-2026-11623
DescriptionA 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.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs1140487

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
tmux (PTS)bullseye3.1c-1+deb11u1vulnerable
bookworm3.3a-3vulnerable
trixie3.5a-3vulnerable
forky3.6b-1fixed
sid3.7-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
tmuxsource(unstable)3.6b-11140487

Notes

[trixie] - tmux <no-dsa> (Minor issue)
[bullseye] - tmux <postponed> (minor issue; hard to exploit)
Fixed by: https://github.com/tmux/tmux/commit/fc6d94a9f8a593bd8b7031650802084385d4ee03 (3.7)
Fixed by: https://github.com/tmux/tmux/commit/b8434182c9ead062be8d50a1ff88e98b41108c1f (3.6b)

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