CVE-2026-3254 — Improper Restriction of Rendered UI Layers or Frames in GitLab

CVE-2026-3254

Improper Restriction of Rendered UI Layers or Frames in GitLab PUBLISHED

Description (CNA)

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.11 before 18.11.1 that under certain conditions could have allowed an authenticated user to load unauthorized content into another user's browser due to improper input validation in the Mermaid sandbox.

Affected (CNA)

Vendor / product	Versions
GitLab / GitLab	affected 18.11 before 18.11.1

CWE

CWE-1021

References

https://hackerone.com/reports/3572752
https://gitlab.com/gitlab-org/gitlab/-/work_items/591587

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.