Authorization Bypass in GitLab CE/EE Affects Multiple Versions
CVE-2025-12653

6.5MEDIUM

Key Information:

Vendor

Gitlab
Status
Gitlab
Vendor
CVE Published:
26 November 2025

What is CVE-2025-12653?

An authorization bypass vulnerability exists in GitLab CE/EE that permits unauthenticated users to join arbitrary organizations. This issue arises from improper header handling under specific conditions. The flaw affects multiple versions of GitLab CE/EE and could be exploited by attackers, thereby compromising the integrity of user management within the application. Prompt updates are recommended to mitigate potential exploitation.

Affected Version(s)

GitLab 18.3 < 18.4.5

GitLab 18.5 < 18.5.3

GitLab 18.6 < 18.6.1

References

https://gitlab.com/gitlab-org/gitlab/-/issues/579372
issue-trackingpermissions-required
https://hackerone.com/reports/3370245
technical-descriptionexploitpermissions-required

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Thanks [pwnie](https://hackerone.com/pwnie) for reporting this vulnerability through our HackerOne bug bounty program
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