CVE-2026-5173: Exposed Dangerous Method or Function in GitLab

Severity: high (CVSS 8.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-08 · updated 2026-07-24
Weakness: CWE-749

Description

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 16.9.6 before 18.8.9, 18.9 before 18.9.5, and 18.10 before 18.10.3 that could have allowed an authenticated user to invoke unintended server-side methods through websocket connections due to improper access control.

Affected products

GitLab: from 16.9.6 before 18.8.9; from 18.9.0 before 18.9.5; from 18.10.0 before 18.10.3 — fixed in 18.10.3, 18.8.9, 18.9.5

How to fix

Upgrade to a fixed version: GitLab 18.10.3, 18.8.9, 18.9.5. Check the vendor advisory for mitigations.

References

https://about.gitlab.com/releases/2026/04/08/patch-release-gitlab-18-10-3-released/
https://gitlab.com/gitlab-org/gitlab/-/work_items/588959

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