Widely used GitLab platform; authenticated-exploit could disrupt CI/CD and project workflows across orgs.
CVE-2026-5173
Authenticated user can invoke unintended server-side methods via GitLab WebSocket.
Is CVE-2026-5173 being exploited?
Not confirmed. CVE-2026-5173 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 0.43% probability of exploitation in the next 30 days.
How severe is CVE-2026-5173?
CVE-2026-5173 is rated High with a CVSS score of 8.5. 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-2026-5173?
Yes. A fix has been recorded for CVE-2026-5173. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-5173 affect?
CVE-2026-5173 affects GitLab CE/EE: 16.9.6–18.8.8; 18.9.x before 18.9.5; 18.10.x before 18.10.3. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-5173?
Patch to fixed versions; review WebSocket access.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated user can trigger unauthorized server-side methods via WebSocket, enabling privilege abuse and potential data impact.
Patch when possible
- affected>= 16.9.6 and < 18.8.9
- affected>= 18.9 and < 18.9.5
- affected>= 18.10 and < 18.10.3
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.