SSRF in Astro \@Astrojs\/node
CVE-2026-25545
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.
Vulnerability class: SSRF (Server-Side Request Forgery)
EPSS: 0.018 (76.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N.
Affected products
- Astro \@Astrojs\/node
- Withastro Astro — versions < 9.5.4
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Third Party Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-25545?
- CVE-2026-25545 is a high-severity vulnerability in Astro \@Astrojs\/node, classified under Server-Side Request Forgery (SSRF). CVSS score: 8.6/10. Published 2026-02-24.
- How severe is CVE-2026-25545?
- High severity. CVSS v3 base score is 8.6 out of 10.