CVE-2025-12734 PUBLISHED

Improper Encoding or Escaping of Output in GitLab

Assigner: GitLab
Reserved: 04.11.2025 Published: 11.12.2025 Updated: 16.12.2025

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.

Metrics

CVSS 3.1

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

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	Low	Integrity Impact	Low
User Interaction	Required	Availability Impact	None

CVSS 3.1

Product Status

Vendor	GitLab
Product	GitLab
Versions	Default: unaffected affected from 15.6 to 18.4.6 (excl.) affected from 18.5 to 18.5.4 (excl.) affected from 18.6 to 18.6.2 (excl.)

Solutions

Upgrade to versions 18.4.6, 18.5.4, 18.6.2 or above.

Credits

Thanks [joaxcar](https://hackerone.com/joaxcar) for reporting this vulnerability through our HackerOne bug bounty program finder

References

Problem Types

CWE-116: Improper Encoding or Escaping of Output CWE