Actively exploited vulnerability
GitLab Community and Enterprise Editions: server-side request forgery flaw under attack
CVE-2021-39935 · GitLab Community and Enterprise Editions Server-Side Request Forgery (SSRF) Vulnerability
What is affected
GitLab Community and Enterprise Editions is mostly run by companies, schools and public bodies, not on home computers. You are unlikely to have it yourself, but organisations that hold your data may. Breaches that start with flaws like this one are how personal data ends up leaked.
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.
What an attacker can do
This is a server-side request forgery flaw. It lets an attacker make the server send requests on their behalf and reach internal systems that are not exposed to the internet.
- How it is reached
- Over the internet or network
- Access the attacker needs
- No account needed
- Does the victim have to do something?
- No, works without the victim doing anything
What to do
- At home: nothing to install. Keep your own devices updated and use a different password for every service, so that a breach at one organisation does not open your other accounts.
- If you administer GitLab Community and Enterprise Editions at work: apply the vendor's fix or mitigation now and review logs for signs of compromise, because the flaw was being exploited before it was listed.
- If the product is past its support date and no fix exists, take it off the internet or retire it.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Vendor advisories and fixes
- about.gitlab.comabout.gitlab.com/releases/2021/12/06/security-release-gitlab-14-5-2-released/
How urgent is it
CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on February 3, 2026, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by February 24, 2026, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.
The EPSS model estimates a 36% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 98% of all scored vulnerabilities.
Its CVSS severity score is 7.5 out of 10 (high), as recorded in the US National Vulnerability Database.
Technical description
An issue has been discovered in GitLab CE/EE affecting all versions starting from 10.5 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2. Unauthorized external users could perform Server Side Requests via the CI Lint API