CVE-2026-84376: Withastro Astro

Medium severity, CVSS 6.3. EPSS: 0.7% chance of exploitation in the next 30 days.

Astro is a web framework for content-driven websites. Prior to 7.2.4, Astro stripped a configured non-root base path from request pathnames using a string-prefix check without verifying a path-segment boundary. With base "/app", a request to "/appX/admin" resolved internally to the protected "/admin" route while middleware observed "/appX/admin" in context.url.pathname. In applications that authorize base-prefixed routes by inspecting context.url.pathname, an unauthenticated remote attacker could bypass pathname-based middleware authorization and reach protected routes. This issue is fixed in version 7.2.4.

Affected products

• Withastro Astro: before 7.2.4 (fixed in 7.2.4)

Published 2026-09-02. Last modified 2026-09-09.