CVE-2026-27829

The record

Astro is a web framework. In versions 9.0.0 through 9.5.3, a bug in Astro's image pipeline allows bypassing `image.domains` / `image.remotePatterns` restrictions, enabling the server to fetch content from unauthorized remote hosts. Astro provides an `inferSize` option that fetches remote images at render time to determine their dimensions. Remote image fetches are intended to be restricted to domains the site developer has manually authorized (using the `image.domains` or `image.remotePatterns` options). However, when `inferSize` is used, no domain validation is performed — the image is fetched from any host regardless of the configured restrictions. An attacker who can influence the image URL (e.g., via CMS content or user-supplied data) can cause the server to fetch from arbitrary hosts. This allows bypassing `image.domains` / `image.remotePatterns` restrictions to make server-side requests to unauthorized hosts. This includes the risk of server-side request forgery (SSRF) against internal network services and cloud metadata endpoints. Version 9.5.4 fixes the issue.

Affected packages

Related vulnerabilities

• GHSA-cj9f-h6r6-4cx2 Astro is vulnerable to SSRF due to missing allowlist enforcement in remote image inferSize Same vulnerability
• CVE-2026-41322 @astrojs/node allows Astro to deploy your SSR site to Node targets. Also affects @astrojs/node
• GHSA-c57f-mm3j-27q9 Astro: Cache Poisoning due to incorrect error handling when if-match header is malformed Also affects @astrojs/node
• GHSA-3rmj-9m5h-8fpv Astro: Memory exhaustion DoS due to missing request body size limit in Server Islands Also affects @astrojs/node
• CVE-2026-29772 Astro is a web framework. Also affects @astrojs/node
• GHSA-jm64-8m5q-4qh8 Astro has memory exhaustion DoS due to missing request body size limit in Server Actions Also affects @astrojs/node
• CVE-2026-27729 Astro is a web framework. Also affects @astrojs/node
• CVE-2026-25545 Astro is a web framework. Also affects @astrojs/node