CVE-2026-57530: Milkdown

Medium severity, CVSS 5.4. EPSS: 0.3% chance of exploitation in the next 30 days.

Milkdown before 7.21.3 contains a stored cross-site scripting vulnerability in the @milkdown/preset-commonmark and @milkdown/components packages that allows attackers with document write access to execute arbitrary JavaScript in the browser context of any user who opens the document or clicks a rendered link. The parseMarkdown runner stores raw URL values from the remark AST as href mark attributes without URL scheme validation, and the ineffective DOMPurify.sanitize call in edit-view.ts treats the bare URL string as a text node and returns it unchanged, allowing javascript: payloads to pass through the link-tooltip preview component and read-only mode anchor elements unmodified.

Affected products

• Milkdown Milkdown: before 7.21.3 (fixed in 7.21.3)

Published 2026-07-24. Last modified 2026-07-27.