mdx-mermaid provides plug and play access to Mermaid in MDX. There is a potential for an arbitrary javascript injection in versions less than 1.3.0 and 2.0.0-rc1. Modify any mermaid code blocks with arbitrary code and it will execute when the component is loaded by MDXjs. This vulnerability was patched in version(s) 1.3.0 and 2.0.0-rc2. There are currently no known workarounds.
https://github.com/sjwall/mdx-mermaid/security/advisories/GHSA-rvgm-35jw-q628
https://github.com/sjwall/mdx-mermaid/commit/f2b99386660fd13316823529c3f1314ebbcdfd2a