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

What is CVE-2026-12635?

CVE-2026-12635 is a server-side request forgery vulnerability in Gitlab Gitlab, published on 25 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official 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.

Weakness: CWE-350

Which versions are affected by CVE-2026-12635?

1 open source package ship an affected version, including gitlab. It affects 1 product.

Products include Gitlab Gitlab.

How do I fix CVE-2026-12635?

Upgrade gitlab to a fixed version for your release line: 18.11.6, 19.0.3 or 19.1.1.

Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.

Is CVE-2026-12635 being exploited?

There is no known exploitation of CVE-2026-12635 in the wild and no public exploit code.

Other vulnerabilities in Gitlab Gitlab

• CVE-2026-97229 GitLab Community Edition and Enterprise Edition Integer Overflow or Wraparound Exploited Critical 10.0
• CVE-2026-85706 GitLab Community Edition and Enterprise Edition Path Traversal Exploited Critical 10.0
• CVE-2023-7028 GitLab Community and Enterprise Editions Improper Access Control Exploited Critical 10.0
• CVE-2021-22205 GitLab Community and Enterprise Editions Remote Code Execution Exploited Critical 10.0
• CVE-2021-39935 GitLab Community and Enterprise Editions Server-Side Request Forgery (SSRF) Exploited Medium 6.8

All Gitlab Gitlab vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-gitlab-2026-12635, GHSA-px7v-hx94-8wmf.