Description
Mermaid does not fully restrict CSS to the rendered SVG subtree. Although selectors are prefixed with #mermaid-X, sibling (~ and +) combinators can still escape the Mermaid container and inject styles to DOM elements adjacent to the diagram <svg>.
Recommendation
Update the mermaid package to the latest compatible version. Followings are version details:
Affected version(s): **< 10.9.8 >= 11.0.0-alpha.1, < 11.16.1** Patched version(s): **10.9.8 11.16.1**
References
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Start a free scanRelated Issues
- Mermaid: Improper sanitization of `classDefs` in diagrams leads to CSS injection - CVE-2026-41148
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See something that needs correcting? Let us knowUpdated August 06, 2026