DOM XSS via unsanitized emoji serialization
Published Jul 24, 2026 · Updated Jul 24, 2026
DOM cross-site scripting in Milkdown before 7.21.3 allows remote attackers to execute JavaScript through attacker-controlled pasted HTML. The emoji parser stores a pasted span's raw innerHTML, and the Markdown serializer assigns that value to a live span instead of sanitizing it or parsing it inertly. Execution requires a victim to paste the crafted span; serialization then runs the payload in the host application's origin on each cycle.
Summary
What happened
DOM cross-site scripting in Milkdown before 7.21.3 allows remote attackers to execute JavaScript through attacker-controlled pasted HTML. The emoji parser stores a pasted span's raw innerHTML, and the Markdown serializer assigns that value to a live span instead of sanitizing it or parsing it inertly. Execution requires a victim to paste the crafted span; serialization then runs the payload in the host application's origin on each cycle.
The record
- CVE
- CVE-2026-57531
- Published
- Jul 24, 2026
- Updated
- Jul 24, 2026
- Vendor
- Milkdown
- Product
- Milkdown
- Classifications
- CWE-79, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 24, 2026CVE publishedPublication date reported by the CVE source.
- Jul 24, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <7.21.3
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Milkdown emoji XSS regression proofproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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