CVE-2025-12734

LOW

GitLab 15.6-18.4.5, 18.5-18.5.3, 18.6-18.6.1 - Authenticated Cross-Site Scripting via Merge Request Title

Title source: llm
STIX 2.1

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.

References (3)

Core 3
Core References
Broken Link issue-tracking permissions-required
https://gitlab.com/gitlab-org/gitlab/-/issues/579573
Permissions Required technical-description exploit permissions-required
https://hackerone.com/reports/3379381

Scores

CVSS v3 3.5
EPSS 0.0023
EPSS Percentile 13.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-116
Status published
Products (1)
gitlab/gitlab 15.6.0 - 18.4.6 (2 CPE variants)
Published Dec 11, 2025
Tracked Since Feb 18, 2026