What is CVE-2020-13321?

CVE-2020-13321 is a high-severity vulnerability in GitLab. CVSS score: 8.3/10. Published 2020-09-30.

How severe is CVE-2020-13321?

High severity. CVSS v3 base score is 8.3 out of 10.

Vulnerability in GitLab

CVE-2020-13321

A vulnerability was discovered in GitLab versions prior to 13.1. Username format restrictions could be bypassed allowing for html tags to be added.

Published 2020-09-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L.

EPSS exploit prediction

EPSS: 0.014 (71.7th percentile), scored 2026-09-28.

Low probability of exploitation in the next 30 days, but still tracked. 72nd percentile — 71.7% 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 <12.10.13, >=13.0, <13.0.8, >=13.1, <13.1.2

References

gitlab.com/gitlab-org/gitlab/-/issues/25751 (Exploit, Vendor Advisory)
gitlab.com/gitlab-org/cves/-/blob/master/2020/CVE-2020-13321.json (Vendor Advisory)

Frequently asked questions

What is CVE-2020-13321?: CVE-2020-13321 is a high-severity vulnerability in GitLab. CVSS score: 8.3/10. Published 2020-09-30.
How severe is CVE-2020-13321?: High severity. CVSS v3 base score is 8.3 out of 10.