CVE-2026-57531

Description

Milkdown before 7.21.3 contains a DOM cross-site scripting vulnerability in the @milkdown/plugin-emoji package that allows unauthenticated attackers to execute arbitrary JavaScript in the host application's origin by causing a victim to paste attacker-controlled content. The parseDOM.getAttrs handler stores raw innerHTML of pasted span elements with data-type="emoji" without sanitization, and the toMarkdown runner subsequently assigns this unsanitized value directly to a live DOM element's innerHTML, bypassing the DOMPurify sanitization used in the toDOM path, causing payload execution on every markdown serialization cycle.

References

• https://github.com/Milkdown/milkdown/commit/db1ae721854a0ab2f188b83cf8695702966640f1
• https://github.com/Milkdown/milkdown/pull/2410
• https://github.com/Milkdown/milkdown/releases/tag/v7.21.3
• https://www.npmjs.com/package/@milkdown/plugin-emoji
• https://www.vulncheck.com/advisories/milkdown-dom-xss-via-innerhtml-assignment