Vulnerability · Published Jun 22, 2026 · Assigned by GitHub_M

CVE-2026-54299Astro: Host-header full-read SSRF in core prerendered error-page fetch (prerenderedErrorPageFetch default + unvalidated createRequestFromNodeRequest URL)

High 7.5

In plain English

A high-severity improper input validation in astro from withastro. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.3%top 73.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Astro is a web framework. Prior to 6.4.6, Astro SSR apps with prerendered error pages (/404 or /500 using export const prerender = true) fetch those pages over HTTP at runtime when an error occurs. The URL for this fetch is derived from request.url, which in turn gets its origin from the incoming Host header. When the Host header is not validated against allowedDomains, an attacker can point the fetch at an arbitrary host and read the response. This vulnerability is fixed in 6.4.6.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	astro	6.4.6	GHSA-2pvr-wf23-7pc7

Affected products (as reported)

Vendor	Product	Versions
withastro	astro	< 6.4.6

Weakness: CWE-20, CWE-918 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:L/A:N

References

https://github.com/withastro/astro/security/advisories/GHSA-2pvr-wf23-7pc7 x_refsource_CONFIRM