# Astro astro@6.3.8 — Release & Upgrade Intelligence
- **Product:** Astro (https://astro.build)
- **Version:** astro@6.3.8
- **Released:** May 26, 2026
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/astro/updates/astro-6.3.8/

## Executive Summary (TL;DR)
Astro astro@6.3.8. Source highlight: Fixes 404s for dynamically imported JS chunks when using an adapter with `assetQueryParams` (e.g. Vercel skew protection)

## Bug Fixes
- Fixes 404s for dynamically imported JS chunks when using an adapter with `assetQueryParams` (e.g. Vercel skew protection)
- Fixes a misleading `GetStaticPathsRequired` error when a redirect is configured from a dynamic route to a static (or less-dynamic) destination. For example, `'/project/[slug]': '/'` previously produced a confusing error pointing at `index.astro`. Astro now detects the parameter mismatch at config validation time and throws a clear `InvalidRedirectDestination` error naming the missing parameters.
- Fixes scoped styles from `.astro` components being dropped when rendered inside MDX content (`<Content />` from `render(entry)`) passed through a named slot using `<Fragment slot="X">`. The Fragment component now eagerly evaluates its slot contents to ensure propagating components register their styles before head content is flushed.
- Fixes missing CSS for conditionally rendered Svelte components in production builds
- Document compressHTML: "jsx" config is only available since Astro v6.2.0
- Fixes a false-positive `Internal Warning: route cache overwritten` logged on every SSR request for dynamic routes

## Upgrade Command
```bash
npm install --save-exact astro@6.3.8
```