CVE-2026-75604: Vercel Next.js

Critical severity, CVSS 9.0. EPSS: 2.1% chance of exploitation in the next 30 days.

Next.js is a React framework for building full-stack web applications. From 13.4.0 until 15.5.24 and 16.3.3, Next.js applications using Pages Router or App Router without Cache Components on Windows-hosted servers do not consistently escape backslashes in route segments before constructing incremental-cache paths. In packages/next/src/shared/lib/router/utils/escape-path-delimiters.ts and packages/next/src/server/lib/incremental-cache/file-system-cache.ts, a remote request can supply encoded Windows path separators that traverse outside the intended cache root and expose private build data, including the server-reference-manifest encryption key. Disclosure of that key can enable remote code execution in the affected application. This issue is fixed in versions 15.5.24 and 16.3.3.

Affected products

• Vercel Next.js: from 13.4.0, before 15.5.24 (fixed in 15.5.24); from 16.0.0, before 16.3.3 (fixed in 16.3.3)

Published 2026-09-01. Last modified 2026-09-09.