Astro is a web framework. Prior to version 9.5.4, Server-Side Rendered pages that return an error with a prerendered custom error page (eg. `404.astro` or `500.astro`) are vulnerable to SSRF. If the `Host:` header is changed to an attacker's server, it will be fetched on `/500.html` and they can redirect this to any internal URL to read the response body through the first request. An attacker who can access the application without `Host:` header validation (eg. through finding the origin IP behind a proxy, or just by default) can fetch their own server to redirect to any internal IP. With this they can fetch cloud metadata IPs and interact with services in the internal network or localhost. For this to be vulnerable, a common feature needs to be used, with direct access to the server (no proxies). Version 9.5.4 fixes the issue.
Metrics
Affected Vendors & Products
References
History
Tue, 24 Feb 2026 00:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Astro is a web framework. Prior to version 9.5.4, Server-Side Rendered pages that return an error with a prerendered custom error page (eg. `404.astro` or `500.astro`) are vulnerable to SSRF. If the `Host:` header is changed to an attacker's server, it will be fetched on `/500.html` and they can redirect this to any internal URL to read the response body through the first request. An attacker who can access the application without `Host:` header validation (eg. through finding the origin IP behind a proxy, or just by default) can fetch their own server to redirect to any internal IP. With this they can fetch cloud metadata IPs and interact with services in the internal network or localhost. For this to be vulnerable, a common feature needs to be used, with direct access to the server (no proxies). Version 9.5.4 fixes the issue. | |
| Title | Astro has Full-Read SSRF in error rendering via Host: header injection | |
| Weaknesses | CWE-918 | |
| References |
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| Metrics |
cvssV4_0
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-02-24T00:37:05.378Z
Reserved: 2026-02-02T19:59:47.375Z
Link: CVE-2026-25545
No data.
Status : Received
Published: 2026-02-24T01:16:13.087
Modified: 2026-02-24T01:16:13.087
Link: CVE-2026-25545
No data.
OpenCVE Enrichment
No data.