CVE-2025-12734 - CVE House
Back to Database
Status published Low CVE-2025-12734

Improper Encoding or Escaping of Output in GitLab

Vulnerability Description

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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

THREAT MONITOR

Am I Vulnerable?

Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2025-12734

Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

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

References

More from GitLab

View All →
CVE-2025-9958
Insertion of Sensitive Information Into Sent Data in GitLab
High 7.7
CVE-2025-9957
Incorrect Authorization in GitLab
Low 2.7
CVE-2025-9825
Missing Authorization in GitLab
Medium 5
CVE-2025-9642
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in GitLab
High 8.7
CVE-2025-9484
Missing Authorization in GitLab
Medium 4.3

Affected Vendor

Affected Software

GitLab
Vulnerable Versions:
15.6, 18.5, 18.6

Timeline

Official Publish: December 11th, 2025
Last Modified: December 16th, 2025
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

Weaknesses (CWE)

CWE-116

MITRE ATT&CK TTPs

T1189 Drive-by Compromise
Initial Access
T1190 Exploit Public-Facing Application
Initial Access
T1059 Command and Scripting Interpreter
Execution
T1565.002 Stored Data Manipulation
Impact