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CVE PROGRAM SOURCE RECORD5.3 Medium

CVE-2026-50159

Mermaid allows CSS injection applying to sibling elements of the diagram

Description

Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Prior to 10.9.8 and 11.16.1, Mermaid is vulnerable to CSS injection via sibling combinator selectors generated from diagram-supplied class or id names. An attacker who can supply diagram text can inject arbitrary CSS into the rendered page, potentially altering the appearance or behavior of unrelated page elements. This issue is fixed in versions 10.9.8 and 11.16.1.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

mermaid-js mermaid

  • < 10.9.8affected
  • >= 11.0.0-alpha.1, < 11.16.1affected

References