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 10.9.0-rc.1 to 11.9.0, user supplied input for sequence diagram labels is passed to innerHTML during calculation of element size, causing XSS.
https://github.com/mermaid-js/mermaid/security/advisories/GHSA-7rqq-prvp-x9jh
https://github.com/mermaid-js/mermaid/commit/685516a85ec1df64cefd4fd15f26533be87d458e
https://github.com/mermaid-js/mermaid/commit/5c69e5fdb004a6d0a2abe97e23d26e223a059832
Published: 2025-08-19
Updated: 2025-08-20
Base Score: 4.3
Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N
Severity: Medium
Base Score: 6.1
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Severity: Medium
Base Score: 5.3
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Severity: Medium
EPSS: 0.00045