Distribution advisory
This page covers CVE-2026-11623 as tracked by Ubuntu, for the package tmux. The fix is available in version 3.6a-2ubuntu0.1; earlier versions remain affected.
How this vulnerability can be exploited
This issue can be reached with local access to the system, attack complexity is high, an attacker needs low-level privileges on the target. No user interaction is required. Rated impact: confidentiality low, integrity low, availability low.
CVSS metrics in full
The score comes from this vector: CVSS:4.0/AV:L/AC:H/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- Attack vector: Local — a local account, shell or session on the host is needed.
- Attack complexity: High — the attacker first has to win a race, learn a secret or otherwise prepare the target.
- Attack requirements: None — no deployment-specific condition has to hold.
- Privileges required: Low — an ordinary user account is enough.
- User interaction: None — nobody has to be tricked into anything.
- Confidentiality impact: Low — limited, and the attacker does not choose what is affected.
- Integrity impact: Low — limited, and the attacker does not choose what is affected.
- Availability impact: Low — limited, and the attacker does not choose what is affected.
Weakness class
UBUNTU-CVE-2026-11623 is classified as CWE-119: Improper Restriction of Operations within Memory Buffer Bounds. A read or write is performed without confirming it stays inside the allocated buffer, corrupting adjacent memory.
Affected software
UBUNTU-CVE-2026-11623 is recorded against 1 package.
- tmux (fixed in 3.6a-2ubuntu0.1)
Timeline and source
Published on 9 June 2026 and last revised on 15 June 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
ubuntu.com (Report)
www.cve.org (Report)
gist.github.com (Report)
github.com (Report)
vuldb.com (Report)
vuldb.com (Report)
vuldb.com (Report)
vuldb.com (Report)
ubuntu.com (Advisory)
Other advisories for this package
tmux has other advisories on record. If you are patching this one, these are worth checking on the same host:
Same weakness in other software
These advisories are the same class of weakness (CWE-119: Improper Restriction of Operations within Memory Buffer Bounds) in other software:
