CVE-2026-41159Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts.
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Prior to 10.9.6 and 11.15.0, Mermaid's default configuration allows injecting CSS that applies outside of the Mermaid diagram via the fontFamily, themeCSS, and altFontFamily configuration options. The injected CSS exploits stylis's & (scope reference) handling. :not(&) escapes the #mermaid-xxx automatic scoping, applying styles to all page elements. Global at-rules (@font-face, @keyframes, @counter-style) are also injectable as stylis hoists them to top level. This allows page defacement and DOM attribute exfiltration via CSS :has() selectors. This vulnerability is fixed in 10.9.6 and 11.15.0.
- CVSS
- 5.3 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Weakness (CWE)
- CWE-94
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Modified
- Record last updated
- Jul 21, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
mermaid_project mermaid mermaid_project:mermaid | before 10.9.6; from 11.0.0 before 11.15.0 | NVD |
References
- https://github.com/mermaid-js/mermaid/commit/64769738d5b59211e1decb471ffbaca8afec51aa
- https://github.com/mermaid-js/mermaid/commit/a9d9f0d8eb790349121508688cd338253fd80d76
- https://github.com/mermaid-js/mermaid/releases/tag/mermaid@11.15.0release-notes
- https://github.com/mermaid-js/mermaid/releases/tag/v10.9.6release-notes
- https://github.com/mermaid-js/mermaid/security/advisories/GHSA-87f9-hvmw-gh4pthird-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.