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.
References
Configurations
Configuration 1 (hide)
|
History
01 Jun 2026, 18:38
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Mermaid Project
Mermaid Project mermaid |
|
| References | () https://github.com/mermaid-js/mermaid/commit/64769738d5b59211e1decb471ffbaca8afec51aahttps://github.com/mermaid-js/mermaid/commit/a9d9f0d8eb790349121508688cd338253fd80d76 - Patch | |
| References | () https://github.com/mermaid-js/mermaid/releases/tag/mermaid@11.15.0 - Release Notes | |
| References | () https://github.com/mermaid-js/mermaid/releases/tag/v10.9.6 - Release Notes | |
| References | () https://github.com/mermaid-js/mermaid/security/advisories/GHSA-87f9-hvmw-gh4p - Third Party Advisory | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.3 |
| CPE | cpe:2.3:a:mermaid_project:mermaid:*:*:*:*:*:node.js:*:* |
29 May 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-29 15:16
Updated : 2026-06-01 18:38
NVD link : CVE-2026-41159
Mitre link : CVE-2026-41159
CVE.ORG link : CVE-2026-41159
JSON object : View
Products Affected
mermaid_project
- mermaid
CWE
CWE-94
Improper Control of Generation of Code ('Code Injection')