CVE-2021-39935Known exploitationNetwork attack vector

Server-side request forgery via CI Lint API

Published Dec 13, 2021 · Updated Feb 3, 2026

SSRF in GitLab CE/EE 10.5 through 14.3.5, 14.4 through 14.4.3, or 14.5 through 14.5.1 allows remote attackers to make server requests. The CI Lint path processes attacker-supplied CI configuration and permits server-side fetch behavior even when an external account has no project assignment. The documented path requires open sign-up with new users designated external; successful requests can disclose information from resources reachable by the server.

CVSS severity6.8
Medium
EPSS probability35.65%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

SSRF in GitLab CE/EE 10.5 through 14.3.5, 14.4 through 14.4.3, or 14.5 through 14.5.1 allows remote attackers to make server requests. The CI Lint path processes attacker-supplied CI configuration and permits server-side fetch behavior even when an external account has no project assignment. The documented path requires open sign-up with new users designated external; successful requests can disclose information from resources reachable by the server.

The record

CVE
CVE-2021-39935
Published
Dec 13, 2021
Updated
Feb 3, 2026
Vendor
GitLab
Product
GitLab
Classifications
CWE-918, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Feb 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>=10.5, <14.3.6
  2. Affected versionversion=>=14.4, <14.4.4
  3. Affected versionversion=>=14.5, <14.5.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

GitLab · GitLabversion=>=10.5, <14.3.6; version=>=14.4, <14.4.4; version=>=14.5, <14.5.2

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
6.8GitLab Inc.CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsShadowserver observations through Sep 16, 2026. Gaps indicate unavailable data.
Sep 10, 2026Sep 16, 2026
View daily counts
Reporting dayUnique IPs
Sep 10, 2026Unavailable
Sep 11, 2026Unavailable
Sep 12, 2026Unavailable
Sep 13, 2026Unavailable
Sep 14, 2026Unavailable
Sep 15, 2026Unavailable
Sep 16, 20262
Latest reporting daySep 16, 2026
Latest daily unique IPs2
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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