Incorrect Regular Expression in Gitlab Community Edition and GitLab Enterprise Edition - CVE-2026-1388
Published: February 26, 2026
Vulnerability identifier: #VU123286
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-1388
CWE-ID: CWE-185
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to insufficient input validation when processing regular expressions in GitLab merge requests. A remote attacker can pass specially crafted data to the application and perform regular expression denial of service (ReDos) attack.
Affected software
Gitlab Community Edition
GitLab Enterprise Edition
GitLab Enterprise Edition
How to mitigate CVE-2026-1388
Install updates from vendor's website.
Gitlab Community Edition - addressed in versions 18.7.5, 18.8.5, 18.9.1
GitLab Enterprise Edition - addressed in versions 18.7.5, 18.8.5, 18.9.1
GitLab Enterprise Edition - addressed in versions 18.7.5, 18.8.5, 18.9.1