GHSA-39h7-pwv7-rc3x
Excalidraw vulnerable to XSS via Mermaid sequence diagram labels (KaTeX rendering)
Quick fix
GHSA-39h7-pwv7-rc3x — @excalidraw/excalidraw: upgrade to the fixed version with the command below.
npm install @excalidraw/excalidraw@0.18.1Details
### Impact
`@excalidraw/excalidraw@0.18.0` depends on a Mermaid conversion package version that resolves to a Mermaid release affected by CVE-2025-54881 / GHSA-7rqq-prvp-x9jh. User-supplied Mermaid sequence diagram labels could trigger XSS through Mermaid’s KaTeX label rendering path.
This is patched in `@excalidraw/excalidraw@0.18.1` by updating `@excalidraw/mermaid-to-excalidraw` to `2.2.2`, which uses a patched Mermaid 11 release.
Moderate severity as this XSS requires manual user action - pasting unsafe Mermaid diagram into the Excalidraw editor. No semi-automated attack vector exists by default (such as accessing a link).
### Patches
- Stable `@excalidraw/excalidraw@0.18.1` is patched. - Unstable `@excalidraw/excalidraw@next` has resolved to patched builds since `@excalidraw/excalidraw@0.18.0-f29edf` on 2025-08-21. - Direct consumers of `@excalidraw/mermaid-to-excalidraw` should use `1.1.3` or later.
### Workarounds
None.
### Resources
- Upstream Mermaid advisory: https://github.com/mermaid-js/mermaid/security/advisories/GHSA-7rqq-prvp-x9jh - CVE-2025-54881
Are you affected?
Enter the version of the package you're using.
Affected packages
0.18.0Fixed in: 0.18.1npm install @excalidraw/excalidraw@0.18.10.3.0Fixed in: 1.1.3npm install @excalidraw/mermaid-to-excalidraw@1.1.3