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Fencer Vulns
medium 5.4

CVE-2026-57530 json

Milkdown < 7.21.3 Stored XSS via javascript: URL in link href

published 2026-07-24 3 mo ago modified 2026-07-27 3 mo ago also EUVD-2026-48735

cvss
5.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 24%
public exploits
0
none known

Summary

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.

Patch / fix

  • Milkdown milkdown 7.21.3

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3 mo ago

Exploit prediction

0.31% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.1 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
CNA 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CNA 4.0 5.1 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected products

  • Milkdown milkdown

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.