CVE-2025-12653

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.3 before 18.4.5, 18.5 before 18.5.3, and 18.6 before 18.6.1 that under specific conditions could have allowed an unauthenticated user to join arbitrary organizations by changing headers on some requests.

CVSS 3.1

6.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

EPSS

0.3% chance of exploitation in the next 30 days; higher than 21% of CVEs (scores of 2026-10-25)

CWE

CWE-290

Published

2025-11-26

Modified

2026-10-18

Record from

the NVD, synced 2026-10-19

Affected

• gitlab:gitlab

References

• https://about.gitlab.com/releases/2025/11/26/patch-release-gitlab-18-6-1-released/
• https://gitlab.com/gitlab-org/gitlab/-/issues/579372
• https://hackerone.com/reports/3370245

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