HighGHSA-26hh-7cqf-hhc6CVE-2026-45109
Next.js has a Middleware / Proxy bypass in App Router applications via segment-prefetch routes - Incomplete Fix Follow-Up
Published 11 May 2026 · Updated 10 Sept 2026
Affected packages
nextnpm
- Affected
- >=15.2.0 <15.5.18
- Fixed in
- 15.5.18
Update to the fixed version for your release line, for example:
npm install next@15.5.18nextnpm
- Affected
- >=16.0.0 <16.2.6
- Fixed in
- 16.2.6
Update to the fixed version for your release line, for example:
npm install next@16.2.6Details
Impact
It was found that the fix addressing CVE-2026-44575 did not apply to middleware.ts with Turbopack. Refer to CVE-2026-44575 for further details.
References
Is GHSA-26hh-7cqf-hhc6 in any of your client repos?
Checking one package by hand is fine. Checking it across forty client projects is not. NPMscan reads the lockfiles in every GitHub repo you pick, finds each project with an affected next, and gives you the command that fixes it.
References
- Linkgithub.com/vercel/next.js/security/advisories/GHSA-267c-6grr-h53f
- Linkgithub.com/vercel/next.js/security/advisories/GHSA-26hh-7cqf-hhc6
- Advisorynvd.nist.gov/vuln/detail/CVE-2026-45109
- Packagegithub.com/vercel/next.js
- Linkgithub.com/vercel/next.js/releases/tag/v15.5.18
- Linkgithub.com/vercel/next.js/releases/tag/v16.2.6
Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.