Mermaid Project: >> Mermaid >> 11.1.0 Security Vulnerabilities
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, there is a denial-of-service attack when rendering gantt charts, if they use the excludes attribute to exclude all dates. mermaid.parse is unaffected, unless you then call the ganttDb.getTasks() (which is called when rendering a diagram). This vulnerability is fixed in 10.9.6 and 11.15.0.
CVSS Score
5.3
EPSS Score
0.0
Published
2026-05-29
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 Score
5.3
EPSS Score
0.0
Published
2026-05-29
Mermaid is a JavaScript based diagramming and charting tool that uses Markdown-inspired text definitions and a renderer to create and modify complex diagrams. In the default configuration of mermaid 11.9.0 and earlier, user supplied input for architecture diagram icons is passed to the d3 html() method, creating a sink for cross site scripting. This vulnerability is fixed in 11.10.0.
CVSS Score
5.1
EPSS Score
0.0
Published
2025-08-19