Vulnerability in GitLab
CVE-2025-2256
An issue has been discovered in GitLab CE/EE affecting all versions from 7.12 before 18.1.6, 18.2 before 18.2.6, and 18.3 before 18.3.2 that could have allowed unauthorized users to render the GitLab instance unresponsive to legitimate users by sending multiple concurrent large SAML responses.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (40.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
Affected products
- GitLab — versions 7.12, 18.2, 18.3
Weakness classification (CWE)
Public proof-of-concept exploits
References
- about.gitlab.com/releases/2025/09/10/patch-release-gitlab-18-3-2-released/ (Release Notes, Vendor Advisory)
- gitlab.com/gitlab-org/gitlab/-/issues/524633 (issue-tracking, permissions-required, Broken Link)
- hackerone.com/reports/3019485 (Permissions Required, technical-description, permissions-required, exploit)
Frequently asked questions
- What is CVE-2025-2256?
- CVE-2025-2256 is a high-severity vulnerability in GitLab, classified under Improper Validation of Specified Quantity in Input. CVSS score: 7.5/10. Published 2025-09-12.
- How severe is CVE-2025-2256?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2025-2256 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.