CVE-2021-39935
GitLab Community and Enterprise Editions Server-Side Request Forgery (SSRF) Vulnerability - [Actively Exploited]
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
INFO
Published Date :
Dec. 13, 2021, 4:15 p.m.
Last Modified :
Feb. 4, 2026, 3:56 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CISA KEV (Known Exploited Vulnerabilities)
For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been 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.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
https://about.gitlab.com/releases/2021/12/06/security-release-gitlab-14-5-2-released/ ; https://nvd.nist.gov/vuln/detail/CVE-2021-39935
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 2.0 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Upgrade to GitLab version 14.3.6, 14.4.4, or 14.5.2 or later.
- Update the affected packages.
Public PoC/Exploit Available at Github
CVE-2021-39935 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-39935.
| URL | Resource |
|---|---|
| https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39935.json | Third Party Advisory |
| https://gitlab.com/gitlab-org/gitlab/-/issues/346187 | Issue Tracking Vendor Advisory |
| https://hackerone.com/reports/1236965 | Permissions Required Third Party Advisory |
| https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39935.json | Third Party Advisory |
| https://gitlab.com/gitlab-org/gitlab/-/issues/346187 | Issue Tracking Vendor Advisory |
| https://hackerone.com/reports/1236965 | Permissions Required Third Party Advisory |
| https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-39935 | US Government Resource |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-39935 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-39935
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-39935 vulnerability anywhere in the article.
-
CybersecurityNews
CISA Warns of GitLab Community and Enterprise Editions SSRF Vulnerability Exploited in Attacks
CISA Warns GitLab SSRF Vulnerability Exploit A critical GitLab vulnerability has been added to the Known Exploited Vulnerabilities (KEV) catalog. Threat actors are actively exploiting a server-side re ... Read more
-
The Hacker News
CISA Adds Actively Exploited SolarWinds Web Help Desk RCE to KEV Catalog
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Tuesday added a critical security flaw impacting SolarWinds Web Help Desk (WHD) to its Known Exploited Vulnerabilities (KEV) catalog ... Read more
-
TheCyberThrone
CISA’s adds 4 vulnerabilitis to KEV Catalog
On February 3, 2026, the Cybersecurity and Infrastructure Security Agency (CISA) updated its Known Exploited Vulnerabilities (KEV) Catalog with four significant vulnerabilities—each backed by evidence ... Read more
The following table lists the changes that have been made to the
CVE-2021-39935 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Modified Analysis by [email protected]
Feb. 04, 2026
Action Type Old Value New Value Changed Reference Type GitLab Inc.: https://gitlab.com/gitlab-org/gitlab/-/issues/346187 Types: Broken Link GitLab Inc.: https://gitlab.com/gitlab-org/gitlab/-/issues/346187 Types: Issue Tracking, Vendor Advisory Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-39935 Types: US Government Resource Changed Reference Type CVE: https://gitlab.com/gitlab-org/gitlab/-/issues/346187 Types: Broken Link CVE: https://gitlab.com/gitlab-org/gitlab/-/issues/346187 Types: Issue Tracking, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Feb. 03, 2026
Action Type Old Value New Value Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-39935 -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Feb. 03, 2026
Action Type Old Value New Value Added CWE CWE-918 -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39935.json Added Reference https://gitlab.com/gitlab-org/gitlab/-/issues/346187 Added Reference https://hackerone.com/reports/1236965 -
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Initial Analysis by [email protected]
Dec. 15, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:N/A:N) Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Changed Reference Type https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39935.json No Types Assigned https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39935.json Third Party Advisory Changed Reference Type https://gitlab.com/gitlab-org/gitlab/-/issues/346187 No Types Assigned https://gitlab.com/gitlab-org/gitlab/-/issues/346187 Broken Link Changed Reference Type https://hackerone.com/reports/1236965 No Types Assigned https://hackerone.com/reports/1236965 Permissions Required, Third Party Advisory Added CWE NIST CWE-918 Added CPE Configuration OR *cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:* versions from (including) 10.5.0 up to (excluding) 14.3.6 *cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:* versions from (including) 10.5.0 up to (excluding) 14.3.6 *cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:* versions from (including) 14.4.0 up to (excluding) 14.4.4 *cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:* versions from (including) 14.4.0 up to (excluding) 14.4.4 *cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:* versions from (including) 14.5.0 up to (excluding) 14.5.2 *cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:* versions from (including) 14.5.0 up to (excluding) 14.5.2
Vulnerability Scoring Details
Base CVSS Score: 7.5
Base CVSS Score: 5
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
53.46 }} 2.94%
score
0.97906
percentile