What’s Vulnerable › Vulnerabilities

CVE-2026-57530: Milkdown < 7.21.3 Stored XSS via javascript: URL in link href

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-24 · updated 2026-07-27
• Weakness: CWE-79

Description

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: before 7.21.3 — fixed in 7.21.3

How to fix

Upgrade to a fixed version: milkdown 7.21.3. Check the vendor advisory for mitigations.

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/components
• https://www.npmjs.com/package/@milkdown/preset-commonmark
• https://www.vulncheck.com/advisories/milkdown-stored-xss-via-javascript-url-in-link-href

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