CVE-2026-57530Network attack vector

Stored XSS via unvalidated javascript link scheme

Published Jul 24, 2026 · Updated Jul 24, 2026

Stored XSS in Milkdown before 7.21.3 allows remote authenticated users with document write access to execute JavaScript through crafted links. The parseMarkdown runner copies raw remark AST URLs into href attributes without scheme validation, while edit-view.ts sanitizes the bare URL as text and leaves javascript: values unchanged. Document write access is required, and execution occurs in a reader's browser when the crafted document is opened or its rendered link is clicked.

CVSS severity5.1
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Milkdown before 7.21.3 allows remote authenticated users with document write access to execute JavaScript through crafted links. The parseMarkdown runner copies raw remark AST URLs into href attributes without scheme validation, while edit-view.ts sanitizes the bare URL as text and leaves javascript: values unchanged. Document write access is required, and execution occurs in a reader's browser when the crafted document is opened or its rendered link is clicked.

The record

CVE
CVE-2026-57530
Published
Jul 24, 2026
Updated
Jul 24, 2026
Vendor
Milkdown
Product
Milkdown
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 24, 2026CVE publishedPublication date reported by the CVE source.
  2. 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.

  1. Affected versionversion=0 <7.21.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Milkdown · Milkdownversion=0 <7.21.3

Published CVSS scores

5.1VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
5.4VulnCheckCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript/JScript

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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