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CVE PROGRAM SOURCE RECORD7.5 High

CVE-2026-44573

Next.js: Middleware / Proxy bypass in Pages Router applications using i18n

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Status
Published
Published
Updated
Assigning organization
GitHub_M

Description

Next.js is a React framework for building full-stack web applications. From 12.2.0 to before 15.5.16 and 16.2.5, Applications using the Pages Router with i18n configured and middleware/proxy-based authorization can allow unauthorized access to protected page data through locale-less /_next/data/<buildId>/<page>.json requests. In affected configurations, middleware does not run for the unprefixed data route, allowing an attacker to retrieve SSR JSON for protected pages without passing the intended authorization checks. This vulnerability is fixed in 15.5.16 and 16.2.5.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

vercel next.js

  • >= 12.2.0, < 15.5.16affected
  • >= 16.0.0, < 16.2.5affected

References