Buffer overflow in Tmux

CVE-2026-11623

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 characteriz…

Vulnerability class: Buffer Overflow

EPSS: 0.001 (2.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.5 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L.

Affected products

  • N/a Tmux — versions 3.6a, 3.7-rc

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-11623?
CVE-2026-11623 is a medium-severity vulnerability in Tmux, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 4.5/10. Published 2026-06-09.
How severe is CVE-2026-11623?
Medium severity. CVSS v3 base score is 4.5 out of 10.