What’s Vulnerable › Vulnerabilities

CVE-2026-12635: Reliance on Reverse DNS Resolution for a Security-Critical Action in GitLab

• Severity: low (CVSS 3.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-25 · updated 2026-06-26
• Weakness: CWE-350

Description

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 8.3 before 18.11.6, 19.0 before 19.0.3, and 19.1 before 19.1.1 that under certain conditions could have allowed an authenticated user with maintainer-role permissions to make requests to internal network resources through mirror synchronization due to improper URL validation.

Affected products

• GitLab: from 8.3.0 before 18.11.6; from 19.0.0 before 19.0.3; 19.1.0 — fixed in 18.11.6, 19.0.3

How to fix

Upgrade to a fixed version: GitLab 18.11.6, 19.0.3. Check the vendor advisory for mitigations.

References

• https://docs.gitlab.com/releases/patches/patch-release-gitlab-19-1-1-released/
• https://gitlab.com/gitlab-org/gitlab/-/work_items/594321

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