CVE-2026-18252

Inclusion of Functionality from Untrusted Control Sphere in GitLab

GitLab has remediated an issue in GitLab EE affecting all versions from 18.9 before 19.1.7, 19.2 before 19.2.5, and 19.3 before 19.3.1 that, under certain conditions, an authenticated user with developer-role permissions could have executed arbitrary commands in a CI context, due to the Claude agent processing configuration from a user-controlled source.

Affected

GitLab

CVSS v3.1 NVD

8.1 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS v3.1 GITLAB

7.3 HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N

EPSS

0.42% chance of exploitation in the next 30 days, 35th percentile

Published

2026-08-26

Updated

2026-08-27

Proof-of-concept exploits (1)

• https://hackerone.com/reports/3863650

Security advisories

• https://docs.gitlab.com/releases/patches/patch-release-gitlab-19-3-1-released
• https://gitlab.com/gitlab-org/gitlab/-/work_items/607342

References

• CVE Record
• NVD entry