CVE-2021-39941

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-12-13 · updated 2026-06-17
Weakness: CWE-200

Description

An information disclosure vulnerability in GitLab CE/EE versions 12.0 to 14.3.6, 14.4 to 14.4.4, and 14.5 to 14.5.2 allowed non-project members to see the default branch name for projects that restrict access to the repository to project members

Affected products

GitLab: from 12.0.0 before 14.3.6; from 14.4.0 before 14.4.4; from 14.5.0 before 14.5.2 — fixed in 14.3.6, 14.4.4, 14.5.2

How to fix

Upgrade to a fixed version: GitLab 14.3.6, 14.4.4, 14.5.2. Check the vendor advisory for mitigations.

References

https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39941.json
https://gitlab.com/gitlab-org/gitlab/-/issues/33864
https://hackerone.com/reports/706361
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39941.json
https://gitlab.com/gitlab-org/gitlab/-/issues/33864
https://hackerone.com/reports/706361

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