GHSA-jmv2-qgxf-f995: Astro: Reflected XSS via unescaped slot names in @astrojs/solid-js

  • Severity: LOW
  • CVE: CVE-2026-126363
  • Ecosystems: npm
  • Packages: @astrojs/solid-js

## Summary

The `@astrojs/solid-js` renderer wraps named slot content passed to Solid components in an “ element, and writes the slot name into its `name` attribute without HTML escaping. A slot name containing `”` could end the attribute and inject arbitrary HTML into the page.

For example, a page that takes a slot name from the request:

“`astro
—
import Tabs from ‘../components/Tabs.jsx’;
const tab = Astro.url.searchParams.get(‘tab’);
—
…
“`

rendered with a Solid component that renders a slot by name:

“`jsx
export default function Tabs(props) {
return {props[props.active]};
}
“`

would output a `tab` value such as `x”>` as live HTML.

## Impact

Reflected cross-site scripting. An attacker who gets a user to open a crafted link can run JavaScript on the site’s origin, but only in applications where all of the following are true:

– The page passes request-controlled input (such as a query parameter) as a slot name.
– The Solid component is hydrated with a `client:*` directive. For non-hydrated components the slot wrapper is removed from the output, together with its `name` attribute.
– The Solid component renders the attacker-chosen slot, which in practice means accessing slot props by a dynamic name. Components that never render the slot only output Astro’s already escaped fallback template.

This is the `@astrojs/solid-js` counterpart of GHSA-8hv8-536x-4wqp (CVE-2026-50146), which fixed the same issue in `astro` core.

## Affected versions

`@astrojs/solid-js…

Source: GitHub Security Advisories · 2026-11-12