CVE-2021-39935

Description

An issue has been discovered in GitLab before version 14.5.2. Unauthorized external users could perform Server Side Requests via the CI Lint API.

Description (MITRE) cveawg.mitre.org

Pulled from cveawg.mitre.org/api/cve/CVE-2021-39935 on 2026-07-27. Shown when MITRE's text differs from the cvelistV5 mirror.

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

Overview

State

—

Assigner (CNA)

—

CVSS severity

—

CVSS score

—

CVSS vector

AV:N/AC:L/Au:N/C:P/I:N/A:N

Effective score

6.8 / 10 MEDIUM source: NVD

CWE(s)

—

Reserved

—

Published

2021-12-13 00:00 UTC

Last updated

—

Source

https://www.rapid7.com/db/vulnerabilities/arch-linux-cve-2021-39935/

CISA Known Exploited Vulnerabilities CISA KEV

CISA has confirmed in-the-wild exploitation of this CVE. Federal agencies must remediate by the due date below; private orgs should treat it as priority-1.

Vulnerability name

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

Vendor / project

GitLab

Product

Community and Enterprise Editions

Date added to KEV

2026-02-03

Remediation due

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.

Ransomware campaign use

Unknown

CISA notes

https://about.gitlab.com/releases/2021/12/06/security-release-gitlab-14-5-2-released/ ; https://nvd.nist.gov/vuln/detail/CVE-2021-39935

CISA listing

www.cisa.gov/known-exploited-vulnerabilities-catalog

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published

2021-12-13 16:15:09 UTC

NVD last modified

2026-06-17 04:04:27 UTC

NVD CVSS v3.1

6.8 / 10 MEDIUM source: cve@gitlab.com

NVD CVSS vector

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

Exploitability subscore

2.2 / 10

Impact subscore

4.0 / 10

EPSS score

0.3565 (probability of exploitation in next 30 days)

EPSS percentile

98.30% vs all CVEs — higher = more likely to be exploited, as of 2026-07-26

NVD-assigned CWE(s): CWE-918 (differs from the CNA list above)

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID

EUVD-2021-26291

Assigner

GitLab

Published

Dec 13, 2021, 3:47:59 PM

Updated

Feb 3, 2026, 5:20:23 PM

EUVD base score (CVSS 3.1)

6.8 / 10
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N

EUVD-reported EPSS

35.6500

Vendors

GitLab

Products

GitLab (10.5, <14.3.6)

GitLab (14.4, <14.4.4)

GitLab (14.5, <14.5.2)

Aliases

GHSA-22hj-9cx7-p2hw

ENISA 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

Vendor references (0)

References embedded in the original CVE record by the assigning CNA.

None in the CVE record.

Web references (8)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

• http://cwe.mitre.org/data/definitions/918.html rapid7:cwe.mitre.org
• https://attackerkb.com/topics/CVE-2021-39935 rapid7:attackerkb.com
• https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-26291 rapid7:euvd.enisa.europa.eu
• https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39935.json rapid7:gitlab.com
• https://gitlab.com/gitlab-org/gitlab/-/issues/346187 rapid7:gitlab.com
• https://hackerone.com/reports/1236965 rapid7:hackerone.com
• https://security.archlinux.org/ASA-202112-10 rapid7:security.archlinux.org
• https://www.cve.org/CVERecord?id=CVE-2021-39935 rapid7:www.cve.org

• CISA Warns of Actively Exploited GitLab SSRF Vulnerability in Community ...
  web:cyberpress.org

  The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has issued a new warning about an actively exploited Server-Side Request Forgery (SSRF) vulnerability in GitLab Community and Enterprise Editions. The flaw, tracked as CVE‑2021‑39935 , allows remote attackers to perform unauthorized server-side requests via the CI Lint API, potentially exposing sensitive internal systems or ...

  2026-06-04 07:52 UTC
• Microsoft Patch Tuesday, September 2025 Edition - Krebs on Security
  web:krebsonsecurity.com

  Microsoft Corp. today issued security updates to fix more than 80 vulnerabilities in its Windows operating systems and software. There are no known "zero-day" or actively exploited ...

  2026-06-04 07:52 UTC
• Security Update Guide - Microsoft
  web:msrc.microsoft.com

  The Microsoft Security Response Center (MSRC) investigates all reports of security vulnerabilities affecting Microsoft products and services, and provides the information here as part of the ongoing effort to help you manage security risks and help keep your systems protected.

  2026-06-04 07:52 UTC
• May 12, 2026-KB5087051 Cumulative Update for .NET Framework 3.5 and 4.8 ...
  web:support.microsoft.com

  The May 12, 2026 update for Windows 11, version 25H2 and Microsoft server operating system 24H2 includes security and cumulative reliability improvements in .NET Framework 3.5 and 4.8.1. We recommend that you apply this update as part of your regular maintenance routines. Before you install this update, see the Prerequisites and Restart requirement sections. Summary Security Improvements CVE ...

  2026-06-04 07:52 UTC
• Microsoft confirms patching issues in restricted Windows networks
  web:www.bleepingcomputer.com

  Microsoft says customers in restricted network environments may encounter Windows Update failures after installing the January 2026 optional non-security preview updates.

  2026-06-04 07:52 UTC
• Microsoft October 2025 Patch Tuesday fixes 6 zero-days, 172 flaws
  web:www.bleepingcomputer.com

  Today is Microsoft's October 2025 Patch Tuesday, which includes security updates for 172 flaws, including six zero-day vulnerabilities. Get patching!

  2026-06-04 07:52 UTC
• February's Patch Tuesday release fixes 59 flaws ... - Computerworld
  web:www.computerworld.com

  Each month, the team at Readiness analyzes the latest Patch Tuesday updates from Microsoft and provides detailed, actionable testing guidance. The company's Patch Tuesday release for February ...

  2026-06-04 07:52 UTC
• Microsoft Confirms Emergency Update For Millions Of Windows Users - Forbes
  web:www.forbes.com

  "Microsoft says it's rolling out an emergency patch that should address localhost-related issues in Windows 11 24H2/25H2, but remember, the hotfix could take longer than 48 hours to show on ...

  2026-06-04 07:52 UTC
• Windows 11 (KB5066835, KB5066793) October 2025 Patch Tuesday out
  web:www.neowin.net

  Microsoft has released Patch Tuesday updates for Windows 11 (KB5066835, KB5066793) for August 2025. Here's what's included.

  2026-06-04 07:52 UTC
• Patch Tuesday June 2026: Security Updates & CVE Analysis
  web:zecurit.com

  Get the complete breakdown of Microsoft's June 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

  2026-06-04 07:52 UTC

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