What’s Vulnerable › Vulnerabilities

CVE-2025-12734: Improper Encoding or Escaping of Output in GitLab

• Severity: low (CVSS 3.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-12-11 · updated 2026-10-14
• Weakness: CWE-116

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.

Affected products

• GitLab: from 15.6.0 before 18.4.6; from 18.5.0 before 18.5.4; from 18.6.0 before 18.6.2 — fixed in 18.4.6, 18.5.4, 18.6.2

How to fix

Upgrade to a fixed version: GitLab 18.4.6, 18.5.4, 18.6.2. Check the vendor advisory for mitigations.

References

• https://about.gitlab.com/releases/2025/12/10/patch-release-gitlab-18-6-2-released/
• https://gitlab.com/gitlab-org/gitlab/-/issues/579573
• https://hackerone.com/reports/3379381

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