CVE-2026-6335

Description

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.11 before 18.11.3 that under certain conditions could have allowed an authenticated user to execute arbitrary code in another user's browser session due to improper sanitization.

CVSS v3.1 Score

5.4

MEDIUM

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

EPSS — Exploit Prediction

0.0003

Probability of exploitation

0.10%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

Affected Products

Vendor	Product	Versions
gitlab	gitlab	18.11.0 — 18.11.3
gitlab	gitlab	18.11.0 — 18.11.3

References

Other References

https://about.gitlab.com/releases/2026/05/13/patch-release-gitlab-18-11-3-released/ https://gitlab.com/gitlab-org/gitlab/-/work_items/596760 https://hackerone.com/reports/3673647

Frequently Asked Questions

What is CVE-2026-6335? +

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.11 before 18.11.3 that under certain conditions could have allowed an authenticated user to execute arbitrary code in another user's browser session due to improper sanitization. It has a CVSS v3.1 base score of 5.4 (MEDIUM).

How severe is CVE-2026-6335? +

CVE-2026-6335 has a CVSS v3.1 score of 5.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0003, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-6335? +

CVE-2026-6335 affects products from gitlab, specifically: gitlab. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-6335? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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