CVE-2021-39910 Cross-site scripting in GitLab

What is CVE-2021-39910?

CVE-2021-39910 is a low-severity cross-site scripting vulnerability in Gitlab Gitlab, published on 13 Dec 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

An issue has been discovered in GitLab CE/EE affecting all versions starting from 12.6 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2. GitLab was vulnerable to HTML Injection through the Swagger UI feature.

Weakness: CWE-79

Which versions are affected by CVE-2021-39910?

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

Products include Gitlab Gitlab.

How do I fix CVE-2021-39910?

Upgrade gitlab to a fixed version for your release line: 14.3.6, 14.4.4 or 14.5.2.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2021-39910 being exploited?

There is no known exploitation of CVE-2021-39910 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-2021-39910, GHSA-9388-pxcv-qr7p, UBUNTU-CVE-2021-39910.