Denial of Service Risk in GitLab CE/EE Affecting Multiple Versions
CVE-2025-2256

7.5HIGH

Key Information:

Vendor

Gitlab
Status
Gitlab
Vendor
CVE Published:
12 September 2025

What is CVE-2025-2256?

A vulnerability has been detected in GitLab CE/EE that affects all versions from 7.12 to prior to 18.1.6, from 18.2 to prior to 18.2.6, and from 18.3 to prior to 18.3.2. This issue can lead to denial of service, allowing unauthorized users to overwhelm the GitLab instance with multiple concurrent large SAML responses, resulting in service unavailability for legitimate users. It is crucial for users to update to the latest versions to mitigate this risk.

Affected Version(s)

GitLab 7.12 < 18.1.6

GitLab 18.2 < 18.2.6

GitLab 18.3 < 18.3.2

References

https://about.gitlab.com/releases/2025/09/10/patch-releas...
https://gitlab.com/gitlab-org/gitlab/-/issues/524633
issue-trackingpermissions-required
https://hackerone.com/reports/3019485
technical-descriptionexploitpermissions-required

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Thanks [yuki_osaki](https://hackerone.com/yuki_osaki) and [lambdasawa](https://hackerone.com/lambdasawa) for reporting this vulnerability through our HackerOne bug bounty program
.
CVE-2025-2256 : Denial of Service Risk in GitLab CE/EE Affecting Multiple Versions