Description
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 5.2 prior to 18.2.8, 18.3 prior to 18.3.4, and 18.4 prior to 18.4.2 that could have allowed an authenticated attacker to create a denial of service condition by configuring malicious webhook endpoints that send crafted HTTP responses.
Affected products
gitlab: gitlab
References3
- about.gitlab.com/releases/2025/10/08/patch-release-gitlab-18-4-… Release NotesVendor Advisory
- gitlab.com/gitlab-org/gitlab/-/issues/528979 Broken Link
- hackerone.com/reports/3058791 Permissions Required
Metrics
- CVSS 3.1
-
6.5
MEDIUM
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 46 · as of 9 November 2026
- CWE
- CWE-770
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.