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Fencer Intel
low 2.3

CVE-2026-126363 json

Astro: Reflected XSS via unescaped slot names in @astrojs/solid-js

published 17d ago modified 2d ago also EUVD-2026-124745 , GHSA-jmv2-qgxf-f995

cvss
2.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 32%
public exploits
0
none known

Summary

Astro is a web framework for content-driven websites. From 0.2.0 until 7.1.2, the @astrojs/solid-js renderer inserted a named slot into the quoted name attribute of an astro-slot wrapper without HTML escaping. A request-controlled slot name containing a quote could terminate the attribute and inject active HTML. Exploitation required a hydrated Solid component using a client:* directive and dynamic access to the attacker-chosen slot property; a component that did not render that slot emitted only escaped fallback content. This issue is fixed in version 7.1.2.

Patch / fix

Is CVE-2026-126363 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 32% of all scored CVEs (FIRST EPSS, 2026-11-14).

CVSS scores

assigned by version score vector
CNA 4.0 2.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
CNA 4.0 2.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/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

Affected packages

ecosystem package affected fixed in
npm @astrojs/solid-js
>=0.2.0, <7.1.2
7.1.2

Affected products

  • withastro astro

Classification

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

References

Sources

Fencer Intel 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.

The maintainers of withastro/astro published their own advisory on GitHub. Reviewed sources take precedence over it.