CVE-2026-41149

Name	CVE-2026-41149
Description	Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Versions 10.9.5 and earlier, as well as 11.0.0-alpha.1 through 11.14.0, are vulnerable to HTML injection under the default configuration. Specifically, the classDef directive in Mermaid state diagrams permits DOM injection that escapes the SVG context. However, <script> tags are stripped, which prevents cross-site scripting (XSS). This issue has been fixed in versions 10.9.6 and 11.15.0. If developers are unable to immediately upgrade, they can work around this issue by setting "securityLevel": "sandbox", which prevents the issue by rendering the mermaid diagram in a sandboxed <iframe>.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
node-mermaid (PTS)	bullseye	8.7.0+ds+~cs27.17.17-3+deb11u2	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
node-mermaid	source	(unstable)	(unfixed)

Notes

[bullseye] - node-mermaid <postponed> (Minor issue, no rdeps)
https://github.com/mermaid-js/mermaid/security/advisories/GHSA-ghcm-xqfw-q4vr
Fixed by: https://github.com/mermaid-js/mermaid/commit/37ff937f1da2e19f882fd1db01235db4d01f4056 (mermaid@11.15.0)
Fixed by: https://github.com/mermaid-js/mermaid/commit/4e2d512bf5bf6f9de1a8f0a48da78dc4d09ac4f3 (v10.9.6)