Vulnerability · Published Sep 12, 2025 · Assigned by GitLab
CVE-2025-2256Improper Validation of Specified Quantity in Input in GitLab
High 7.5
In plain English
A high-severity security flaw in GitLab from GitLab. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities).
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.5%top 55.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected products (as reported)
Weakness: CWE-1284 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://about.gitlab.com/releases/2025/09/10/patch-release-gitlab-18-3-2-released/
- GitLab Issue #524633 issue-tracking, permissions-required
- HackerOne Bug Bounty Report #3019485 technical-description, exploit, permissions-required