What is CVE-2026-1090?

CVE-2026-1090 is a high-severity vulnerability in Gitlab, classified under Cross-site Scripting. CVSS score: 8.7/10. Published 2026-03-11.

How severe is CVE-2026-1090?

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

XSS in Gitlab

CVE-2026-1090

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 10.6 before 18.7.6, 18.8 before 18.8.6, and 18.9 before 18.9.2 that could have allowed an authenticated user, when the `markdown_placeholders` feature flag was enab…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.001 (24.7th percentile) — read the EPSS interpretation.

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.

Affected products

Gitlab — versions 10.6, 18.8, 18.9

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

HackerOne Bug Bounty Report #3502450 (technical-description, exploit, permissions-required)
gitlab.com/gitlab-org/gitlab/-/work_items/586478
about.gitlab.com/releases/2026/03/11/patch-release-gitlab-18-9-2-released/

Frequently asked questions

What is CVE-2026-1090?: CVE-2026-1090 is a high-severity vulnerability in Gitlab, classified under Cross-site Scripting. CVSS score: 8.7/10. Published 2026-03-11.
How severe is CVE-2026-1090?: High severity. CVSS v3 base score is 8.7 out of 10.