What is CVE-2018-20490?

CVE-2018-20490 is a medium-severity vulnerability in GitLab, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2019-12-30.

How severe is CVE-2018-20490?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in GitLab

CVE-2018-20490

An issue was discovered in GitLab Community and Enterprise Edition 11.2.x through 11.4.x before 11.4.13, 11.5.x before 11.5.6, and 11.6.x before 11.6.1. It allows XSS.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2019-12-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.006 (46.4th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

GitLab

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

about.gitlab.com/2018/12/31/security-release-gitlab-11-dot-6-dot-1-released/ (Vendor Advisory)
gitlab.com/gitlab-org/gitlab-ce/issues/54377 (Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2018-20490?: CVE-2018-20490 is a medium-severity vulnerability in GitLab, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2019-12-30.
How severe is CVE-2018-20490?: Medium severity. CVSS v3 base score is 5.4 out of 10.