GitLab is widely used; unauthenticated XSS could disrupt many orgs and CI/CD workflows.
CVE-2026-5816
Unauthenticated JavaScript execution in GitLab sessions via path validation flaw.
Is CVE-2026-5816 being exploited?
Not confirmed. CVE-2026-5816 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.41% probability of exploitation in the next 30 days.
How severe is CVE-2026-5816?
CVE-2026-5816 is rated High with a CVSS score of 8.0. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-5816?
Yes. A fix has been recorded for CVE-2026-5816. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-5816 affect?
CVE-2026-5816 affects GitLab CE, GitLab EE. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-5816?
Patch to 18.10.4 or 18.11.1+ (or latest).
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated JS runs in a victim's browser; potential session hijack and token theft in GitLab UI.
Immediate action required
- affected>= 18.10 and < 18.10.4
- affected>= 18.11 and < 18.11.1
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.