CVE-2021-39885

Severity: medium (CVSS 5.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-10-04 · updated 2026-06-17
Weakness: CWE-79

Description

A Stored XSS in merge request creation page in all versions of Gitlab EE starting from 13.7 before 14.1.7, all versions starting from 14.2 before 14.2.5, and all versions starting from 14.3 before 14.3.1 allows an attacker to execute arbitrary JavaScript code on the victim's behalf via malicious approval rule names

Affected products

GitLab: from 13.7.0 before 14.1.7; from 14.2.0 before 14.2.5; 14.3.0 — fixed in 14.1.7, 14.2.5

How to fix

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

References

https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39885.json
https://gitlab.com/gitlab-org/gitlab/-/issues/341140
https://hackerone.com/reports/1342009
https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39885.json
https://gitlab.com/gitlab-org/gitlab/-/issues/341140
https://hackerone.com/reports/1342009

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