Exploited vulnerabilities / CVE-2021-39935

Confirmed exploited · server-side request forgery · GitLab Community and Enterprise Editions

CVE-2021-39935

GitLab Community and Enterprise Editions server-side request forgery, confirmed exploited in the wild.

GitLab Community and Enterprise Editions contain a server-side request forgery vulnerability which could allow unauthorized external users to perform Server Side Requests via the CI Lint API.

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36%chance of exploitation in the next 30 days (EPSS), 98th percentile

3 Febadded to CISA's Known Exploited Vulnerabilities list, 2026

24 Febfederal remediation deadline, already passed

Passedpast the deadline: patch now

CISA's name for it	GitLab Community and Enterprise Editions Server-Side Request Forgery (SSRF) Vulnerability
Vendor and product	GitLab · Community and Enterprise Editions
Type	server-side request forgery · CWE-918
Exploited	Confirmed by CISA listed 3 February 2026
Likelihood	one of the most likely to be exploited of every vulnerability tracked
Deadline	24 February 2026 · already passed
Used in ransomware	Not reported
Advisories	about.gitlab.com ↗ · nvd.nist.gov ↗

What to do

Three steps, in this order

Step 1

Apply the vendor's fix or mitigation; CISA lists only vulnerabilities seen exploited.

Step 2

If you cannot patch now, restrict network access to the affected product.

Step 3

Check for signs of compromise since the date it was added to the list.

CISA's 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.

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Questions

CVE-2021-39935 in short

Is CVE-2021-39935 being exploited?

Yes. CISA added CVE-2021-39935 to its Known Exploited Vulnerabilities catalogue on 3 February 2026, which it does only on evidence of exploitation in the wild.

What is the CISA deadline for CVE-2021-39935?

US federal agencies must remediate it by 24 February 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.

How likely is CVE-2021-39935 to be exploited in the next 30 days?

FIRST's Exploit Prediction Scoring System gives it 36%, the 98th percentile of every CVE it scores.

How do I fix CVE-2021-39935?

Apply the vendor's fix or mitigation; CISA lists only vulnerabilities seen exploited. If you cannot patch now, restrict network access to the affected product. Check for signs of compromise since the date it was added to the list.

Same vendor

Other GitLab vulnerabilities being exploited

CVE	Product	Type	Listed
CVE-2026-97229	Community Edition and Enterprise Edition	remote code execution	29 October 2026
CVE-2026-85706	Community Edition and Enterprise Edition	authentication bypass	11 September 2026
CVE-2021-22175	GitLab	server-side request forgery	18 February 2026

Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.