CVE-2026-73424

Name of the Vulnerable Software and Affected Versions Astro versions 10.0.3 through 11.0.2

Description The Astro Vercel adapter contains a confused deputy problem where the serverless entrypoint allows unauthenticated requests to determine which route the origin renders. When Incremental Static Regeneration (ISR) is enabled, the public / isr function reads the x astro path query parameter and rewrites the request path to it without authentication. Because Vercel sets the x-vercel-isr header on requests to this function, including direct external requests, an attacker can bypass edge-level access controls. This affects applications using @astrojs/vercel with isr: true that protect routes via Vercel path rules, firewall deny rules, or split deployments where authorization is handled by edge middleware. An attacker can read any GET rendered route by requesting / isr?x astro path=/the/protected/path. This issue is located in the packages/integrations/vercel/src/serverless/entrypoint.ts file.

Recommendations Update Astro to version 11.0.3. As a temporary workaround, restrict access to the / isr endpoint or disable the isr: true configuration in the Vercel adapter.