CVE-2026-54299

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

HIGH
7.5
CVSS Score
Published: June 22, 2026 at 05:33 PM UTC
Updated: October 25, 2026 at 11:10 PM UTC
2 products affected across 2 vendorsAstroAstro

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Severity
HIGH7.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

All versionsv < 6.4.6
Affected range stops below 6.4.6, so it looks safe — our inference, not a vendor statement
v < 6.4.6
Affected range stops below 6.4.6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

x_refsource_CONFIRMMitigationVendor Advisory
Source: cverecord
https://github.com/withastro/astro/security/advisories/GHSA-2pvr-wf23-7pc7

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-20CWE-918

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