CVE-2026-57531
Milkdown < 7.21.3 DOM XSS via innerHTML Assignment
- State
- Published
- Severity
- 5.1 Medium
- Published
- Jul 24, 2026
- Updated
- Jul 25, 2026
- Reserved
- Jun 24, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.1 Medium | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N | VulnCheck |
| 3.1 | 5.4 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N | VulnCheck |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
milkdownMilkdown |
|
References
- Milkdown 7.21.3 Release Notesrelease-notespatch
- Pull Requestissue-trackingpatch
- Patch Commitpatch
- @milkdown/plugin-emojiproduct
- https://www.vulncheck.com/advisories/milkdown-dom-xss-via-innerhtml-assignmentthird-party-advisory
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