CVE-2026-84739

HIGH 8.7

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') in GitLab

CVSS Score

8.7

EPSS Score

0.0%

EPSS Percentile

0th

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 13.11 before 19.2.7, 19.3 before 19.3.3, and 19.4 before 19.4.1 that under certain conditions could have allowed an authenticated user to execute arbitrary JavaScript in the context of another user's browser session due to improper sanitization of path components in the merge request diff viewer.

CWE	CWE-79
Vendor	gitlab
Product	gitlab
Ecosystems	DevTools
Industries	Technology
Published	Sep 29, 2026

Stay Ahead of the Next One

Get instant alerts for gitlab gitlab

Be the first to know when new high vulnerabilities affecting gitlab gitlab are published — delivered to Slack, Telegram or Discord.

Get Free Alerts → Free · No credit card · 60 sec setup

CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Affected Versions

GitLab / GitLab

13.11 < 19.2.7 19.3 < 19.3.3 19.4 < 19.4.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

gitlab.com: https://gitlab.com/gitlab-org/gitlab/-/work_items/627316 hackerone.com: https://hackerone.com/reports/3938482 docs.gitlab.com: https://docs.gitlab.com/releases/patches/patch-release-gitlab-19-4-1-released/

Credits

Thanks [joaxcar](https://hackerone.com/joaxcar) for reporting this vulnerability through our HackerOne bug bounty program