What is CVE-2021-39876?

CVE-2021-39876 is a medium-severity vulnerability in GitLab, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2022-03-28.

How severe is CVE-2021-39876?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Auth bypass in GitLab

CVE-2021-39876

In all versions of GitLab CE/EE since version 11.3, the endpoint for auto-completing Assignee discloses the members of private groups.

Vulnerability class: Broken Access Control

Published 2022-03-28 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.009 (59.3th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 59.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

GitLab — versions >=11.3, <14.1.7, >=14.2, <14.2.5, >=14.3, <14.3.1

Weakness classification (CWE)

CWE-863 — Incorrect Authorization

References

gitlab.com/gitlab-org/gitlab/-/issues/29683 (Exploit, Issue Tracking, Vendor Advisory)
hackerone.com/reports/627507 (Permissions Required, Third Party Advisory)
gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-39876.json (Vendor Advisory)

Frequently asked questions

What is CVE-2021-39876?: CVE-2021-39876 is a medium-severity vulnerability in GitLab, classified under Incorrect Authorization. CVSS score: 4.3/10. Published 2022-03-28.
How severe is CVE-2021-39876?: Medium severity. CVSS v3 base score is 4.3 out of 10.