Vulnerability · Published Jul 24, 2026 · Assigned by VulnCheck

CVE-2026-57531Milkdown < 7.21.3 DOM XSS via innerHTML Assignment

Medium 5.4

In plain English

A medium-severity cross-site scripting in milkdown from Milkdown. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities).

Severity (CVSS 3.1)5.4Medium

Exploit odds (30 days)0.4%top 65.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
Milkdown	milkdown	0 – before 7.21.3

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

References

Milkdown 7.21.3 Release Notes release-notes, patch
Pull Request issue-tracking, patch
Patch Commit patch
@milkdown/plugin-emoji product
https://www.vulncheck.com/advisories/milkdown-dom-xss-via-innerhtml-assignment third-party-advisory