Description
Next.js is a React framework for building full-stack web applications. From 15.0.0 until 15.5.27 and 16.3.8, applications with a root-level catch-all page and statically generated or Incremental Static Regeneration routes can use a shared response cache key that is insufficiently scoped to the source route. A single unauthenticated crafted request can poison that cache, causing cross-user content substitution or persistent denial of service until the poisoned entry is revalidated or replaced. This issue is fixed in versions 15.5.27 and 16.3.8.
Affected products
vercel: next.js
References5
- github.com/vercel/next.js/security/advisories/GHSA-mcj8-r9mp-w4… Vendor Advisory
- github.com/vercel/next.js/commit/52c94abdd2ea5f416f5e8353ea8a2e… Patch
- github.com/vercel/next.js/commit/719e4c67d6e92df60246f95e1d96e2… Patch
- github.com/vercel/next.js/releases/tag/v15.5.27 Release Notes
- github.com/vercel/next.js/releases/tag/v16.3.8 Release Notes
Metrics
- CVSS 3.1
-
4.8
MEDIUM
Score source: NVD
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L - CVSS 4.0
-
6.3
MEDIUM
Score source: CNA
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 16 · as of 10 November 2026
- CWE
- CWE-524
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.