CVE-2021-39889

Severity: medium (CVSS 4.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-10-05 · updated 2026-06-17
Weakness: CWE-639

Description

In all versions of GitLab EE since version 14.1, due to an insecure direct object reference vulnerability, an endpoint may reveal the protected branch name to a malicious user who makes a crafted API call with the ID of the protected branch.

Affected products

GitLab: from 14.1.0 before 14.1.7; from 14.2.0 before 14.2.5; from 14.3.0 before 14.3.1 — fixed in 14.1.7, 14.2.5, 14.3.1

How to fix

Upgrade to a fixed version: GitLab 14.1.7, 14.2.5, 14.3.1. Check the vendor advisory for mitigations.

References

https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39889.json
https://gitlab.com/gitlab-org/gitlab/-/issues/338062
https://hackerone.com/reports/1294017
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39889.json
https://gitlab.com/gitlab-org/gitlab/-/issues/338062
https://hackerone.com/reports/1294017

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