CVE-2021-39935
HighExploitedPublic exploitUnauthorized external users could perform Server Side Requests via the CI Lint API
Published Dec 14, 2021 · Updated Sep 8, 2026 · Also known as BIT-gitlab-2021-39935, UBUNTU-CVE-2021-39935
Key Facts
Patch immediately- CVE-2021-39935 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting GitLab.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 11, 2025. Public exploit code is available.
- EPSS estimates a 36% probability of exploitation in the next 30 days.
- Fixed versions are available, including GitLab 14.3.6, GitLab 14.4.4, GitLab 14.5.2.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS (30-day exploit likelihood)
36%
Higher than 98.4% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2021-39935 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Feb 3, 2026 | Feb 24, 2026 | Not reported |
| Industry KEV feed | Mar 11, 2025 | Feb 24, 2026 | Not reported |
| CIRCL KEV | Feb 3, 2026 | Feb 24, 2026 | Not reported |
| ENISA EUVD | Feb 3, 2026 | n/a | Not reported |
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.
Affected Products
7 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| GitLabGitlab | >= 10.5.0, >= >=10.5, <14.3.6 | 14.3.6 |
Patched Releases
GitLab
14.3.6, 14.4.4, 14.5.2, 14.5.2-1, 15.10.8+ds1-2
Timeline
Publicly disclosed
Dec 14, 2021
Added to Industry KEV feed
Mar 11, 2025
Added to CISA KEV
Feb 3, 2026
Added to CIRCL KEV
Feb 3, 2026
Added to ENISA EUVD
Feb 3, 2026
Last updated
Sep 8, 2026
Weakness Type
- CWE-918 Server-Side Request Forgery (SSRF)
References
- advisoryhttps://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39935.json
- advisoryhttps://gitlab.com/gitlab-org/gitlab/-/issues/346187
- advisoryhttps://hackerone.com/reports/1236965
- advisoryhttps://ubuntu.com/security/CVE-2021-39935
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-39910
FAQ
Common Questions.
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.
Affected: GitLab versions >= 10.5.0, >= >=10.5, <14.3.6. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 11, 2025.
Yes. It was added on Feb 3, 2026 with a federal remediation due date of Feb 24, 2026.
Public exploit code is available.
Fixed versions are available, including GitLab 14.3.6, GitLab 14.4.4, GitLab 14.5.2.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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