What is CVE-2020-13270?

CVE-2020-13270 is a high-severity vulnerability in GitLab, classified under Missing Authorization. CVSS score: 7.5/10. Published 2020-06-10.

How severe is CVE-2020-13270?

High severity. CVSS v3 base score is 7.5 out of 10.

Auth bypass in GitLab

CVE-2020-13270

Missing permission check on fork relation creation in GitLab CE/EE 11.3 and later through 13.0.1 allows guest users to create a fork relation on restricted public projects via API

Vulnerability class: Broken Access Control

Published 2020-06-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.014 (71.6th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 72nd percentile — 71.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.014 · newest: 0.014 · change: 0.000

Affected products

GitLab — versions >=11.3, <12.9.8, >=12.10, <12.10.7, >=13.0, <13.0.1

Weakness classification (CWE)

CWE-862 — Missing Authorization

References

gitlab.com/gitlab-org/gitlab/-/issues/24648 (Broken Link, Vendor Advisory)
hackerone.com/reports/419977 (Permissions Required, Third Party Advisory)
gitlab.com/gitlab-org/cves/-/blob/master/2020/CVE-2020-13270.json (Vendor Advisory)

Frequently asked questions

What is CVE-2020-13270?: CVE-2020-13270 is a high-severity vulnerability in GitLab, classified under Missing Authorization. CVSS score: 7.5/10. Published 2020-06-10.
How severe is CVE-2020-13270?: High severity. CVSS v3 base score is 7.5 out of 10.