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MEDIUM · CVSS 6.8 CISA Known Exploited Vulnerability

CVE-2021-39935

GitLab Community and Enterprise Editions Server-Side Request Forgery (SSRF) Vulnerability

GitLab Community and Enterprise Editions

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

CVSS
6.8
MEDIUM
EPSS
36.1%
30-day exploitation
Ransomware groups
0
recorded exploiting
Published
13 Dec 2021
CWE-918

Exploitation status

CISA Known Exploited Vulnerabilities

Listed by CISA on 3 February 2026. US federal agencies were required to remediate it by 24 February 2026.

EPSS — exploitation probability

FIRST puts the probability of exploitation activity in the next 30 days at 36.1%, which is higher than 98.5% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N

Frequently asked questions

Is CVE-2021-39935 being exploited by ransomware groups?

No ransomware group in this database is currently recorded as exploiting CVE-2021-39935.

What does CVE-2021-39935 affect?

CVE-2021-39935 affects GitLab Community and Enterprise Editions. 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

How severe is CVE-2021-39935?

CVE-2021-39935 is rated MEDIUM with a CVSS base score of 6.8. EPSS puts the probability of exploitation in the next 30 days at 36.1%, higher than 98.5% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 24 February 2026.

How should organisations respond to CVE-2021-39935?

Apply the vendor patch for GitLab Community and Enterprise Editions as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.