Cross-site scripting in Gitlab Community Edition and GitLab Enterprise Edition - CVE-2026-6335
Published: May 18, 2026
Vulnerability identifier: #VU131678
CSH Severity: Low
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N]
CVE-ID: CVE-2026-6335
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to execute arbitrary code in another user's browser session.
The vulnerability exists due to improper sanitization in Banzai markdown sanitizer when rendering crafted markdown content. A remote user can inject crafted script content to execute arbitrary code in another user's browser session.
User interaction is required to view the crafted content.
Affected software
Gitlab Community Edition
GitLab Enterprise Edition
GitLab Enterprise Edition
How to mitigate CVE-2026-6335
Install security update from vendor's website.
Gitlab Community Edition - update to 18.11.3
GitLab Enterprise Edition - update to 18.11.3
GitLab Enterprise Edition - update to 18.11.3