Actively exploited · Published Dec 13, 2021 · Assigned by GitLab
CVE-2021-39935
Medium 6.8 Exploited
In plain English
A medium-severity server-side request forgery in GitLab from GitLab. Attackers are actively exploiting it in the wild (listed by CISA on February 3, 2026). The chance it is exploited in the next 30 days is estimated at 36.1% (higher than 98% of all known vulnerabilities). Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA guidance
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Federal agencies must remediate by Feb 24, 2026.
Official 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
Affected products (as reported)
Weakness: CWE-918 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N
References
- https://gitlab.com/gitlab-org/gitlab/-/issues/346187 x_refsource_MISC
- https://hackerone.com/reports/1236965 x_refsource_MISC
- https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39935.json x_refsource_CONFIRM
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-39935 government-resource