CVE-2025-12734

Improper Encoding or Escaping of Output in GitLab

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 15.6 before 18.4.6, 18.5 before 18.5.4, and 18.6 before 18.6.2 that could have allowed an authenticated user to, under certain conditions, render content in dialogs to other users by injecting malicious HTML content into merge request titles.

Affected

GitLab

CVSS v3.1 GITLAB

3.5 LOWCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

EPSS

0.27% chance of exploitation in the next 30 days, 18th percentile

Published

2025-12-11

Updated

2025-12-16

Proof-of-concept exploits (1)

• https://hackerone.com/reports/3379381

Security advisories

• https://about.gitlab.com/releases/2025/12/10/patch-release-gitlab-18-6-2-released

References

• CVE Record
• NVD entry