What is CVE-2021-22242?

CVE-2021-22242 is a high-severity vulnerability in GitLab, classified under Cross-site Scripting. CVSS score: 8.7/10. Published 2021-08-25.

How severe is CVE-2021-22242?

High severity. CVSS v3 base score is 8.7 out of 10.

XSS in GitLab

CVE-2021-22242

Insufficient input sanitization in Mermaid markdown in GitLab CE/EE version 11.4 and up allows an attacker to exploit a stored cross-site scripting vulnerability via a specially-crafted markdown

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-08-25 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.636 (99.2th percentile), scored 2026-10-29.

High probability of exploitation in the next 30 days — patch promptly. 99th percentile — 99.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.636 · newest: 0.636 · change: 0.000

Affected products

GitLab — versions >=11.4, <13.12.9, >=14.0, <14.0.7, >=14.1, <14.1.2

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

gitlab.com/gitlab-org/gitlab/-/issues/332528 (Broken Link)
hackerone.com/reports/1212822 (Permissions Required, Third Party Advisory)
gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-22242.json (Vendor Advisory)

Frequently asked questions

What is CVE-2021-22242?: CVE-2021-22242 is a high-severity vulnerability in GitLab, classified under Cross-site Scripting. CVSS score: 8.7/10. Published 2021-08-25.
How severe is CVE-2021-22242?: High severity. CVSS v3 base score is 8.7 out of 10.