What is CVE-2019-5466?

CVE-2019-5466 is a medium-severity vulnerability in GitLab, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 4.3/10. Published 2020-01-28.

How severe is CVE-2019-5466?

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

Auth bypass in GitLab

CVE-2019-5466

An IDOR was discovered in GitLab CE/EE 11.5 and later that allowed new merge requests endpoint to disclose label names.

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published 2020-01-28 · 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: 0.010 (60.6th percentile), scored 2026-10-04.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 61st percentile — 60.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

GitLab
GitLab Ce/ee — versions Affects GitLab CE/EE 11.5 and later, Fixed in 12.1.2 in 12.0.4 and in 11.11.6

Weakness classification (CWE)

CWE-639 — Authorization Bypass Through User-Controlled Key

References

about.gitlab.com/releases/2019/07/29/security-release-gitlab-12-dot-1-dot-2-rel… (Patch, Release Notes, Vendor Advisory)
hackerone.com/reports/507113 (Permissions Required)
gitlab.com/gitlab-org/gitlab-ce/issues/59809 (Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2019-5466?: CVE-2019-5466 is a medium-severity vulnerability in GitLab, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 4.3/10. Published 2020-01-28.
How severe is CVE-2019-5466?: Medium severity. CVSS v3 base score is 4.3 out of 10.