How severe is CVE-2021-39935?

CVE-2021-39935 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-39935?

Affected package information for CVE-2021-39935 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2021-39935?

No fixed version has been published for CVE-2021-39935 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2021-39935 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-39935 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-39935?

CVE-2021-39935 has an EPSS (Exploit Prediction Scoring System) score of 64.5%, placing it in the 98th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2021-39935 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2021-39935 (GitLab Community and Enterprise Editions Server-Side Request Forgery (SSRF) Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-02-03. CISA required all US federal civilian agencies to remediate this vulnerability by 2026-02-24. The required action was: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2021-39935?

CVE-2021-39935 is classified as Server-Side Request Forgery (SSRF) (CWE-918). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2021-39935 published, and has it been updated?

CVE-2021-39935 was published on December 13, 2021 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2021-39935: high severity vulnerability (CVSS 7.5)

EPSS Exploitation Probability

via FIRST.org ↗

64.5%probability of exploitation in next 30 days

High Risk98th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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

Frequently Asked 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. Unauthorized external users could perform Server Side Requests via the CI Lint API

O3 Security · Impact-Aware SCA

Is CVE-2021-39935 in your stack?

O3 detects CVE-2021-39935 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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