What is CVE-2021-39935?

CVE-2021-39935 is a medium-severity vulnerability in Gitlab. CVSS score: 6.8/10. Published 2021-12-13.

How severe is CVE-2021-39935?

Medium severity. CVSS v3 base score is 6.8 out of 10.

Is CVE-2021-39935 known to be exploited?

Yes. CVE-2021-39935 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-02-03), indicating it is being actively exploited. 2 public proof-of-concept repositories are indexed.

Vulnerability in Gitlab

CVE-2021-39935

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 S…

EPSS: 0.645 (98.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N.

Affected products

Gitlab — versions >=10.5, <14.3.6, >=14.4, <14.4.4, >=14.5, <14.5.2

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2026-02-03. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2026-02-24.

Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Public proof-of-concept exploits

References

gitlab.com/gitlab-org/gitlab/-/issues/346187 (x_refsource_MISC)
hackerone.com/reports/1236965 (x_refsource_MISC)
gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39935.json (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2021-39935?: CVE-2021-39935 is a medium-severity vulnerability in Gitlab. CVSS score: 6.8/10. Published 2021-12-13.
How severe is CVE-2021-39935?: Medium severity. CVSS v3 base score is 6.8 out of 10.
Is CVE-2021-39935 known to be exploited?: Yes. CVE-2021-39935 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-02-03), indicating it is being actively exploited. 2 public proof-of-concept repositories are indexed.