CVE-2021-39935 GitLab Community and Enterprise Editions: web page flaw
In plain words: A web app can be made to act on someone's behalf or reach places it should not. Stolen sessions, actions taken as the victim, or access to internal systems.
Confirmed exploited by CISA on · US federal patch deadline Feb 24, 2026
What to do
- Install GitLab's security update for Community and Enterprise Editions. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- GitLab Community and Enterprise Editions Server-Side Request Forgery (SSRF) Vulnerability
- Product
- GitLab Community and Enterprise Editions
- CISA description
- GitLab Community and Enterprise Editions contain a server-side request forgery vulnerability which could allow unauthorized external users to perform Server Side Requests via the CI Lint API.
- Type of flaw
- Web page flaw (CWE-918)
- Confirmed exploited
- Feb 3, 2026
- US federal patch deadline
- Feb 24, 2026
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Answering about CVE-2021-39935 ·
Questions about CVE-2021-39935
Is CVE-2021-39935 being exploited?
Yes. CISA added CVE-2021-39935 to its Known Exploited Vulnerabilities catalog on Feb 3, 2026, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2021-39935?
Install GitLab's security update for Community and Enterprise Editions. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2021-39935?
Only if you use GitLab Community and Enterprise Editions. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.