Vulnerability · Published Oct 2, 2026 · Assigned by GitHub_M
CVE-2026-94484Next.js: Cache poisoning in Next.js SSG/ISR rendering leads to cross-user content substitution and persistent denial of service
Medium 6.3
In plain English
A medium-severity security flaw in next.js from vercel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | next | 16.3.8 | GHSA-mcj8-r9mp-w47p |
| npm | next | 15.5.27 | GHSA-mcj8-r9mp-w47p |
Affected products (as reported)
Weakness: CWE-524 · Vector: 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
References
- https://github.com/vercel/next.js/security/advisories/GHSA-mcj8-r9mp-w47p x_refsource_CONFIRM
- https://github.com/vercel/next.js/commit/52c94abdd2ea5f416f5e8353ea8a2edd3fe311b8 x_refsource_MISC
- https://github.com/vercel/next.js/commit/719e4c67d6e92df60246f95e1d96e2dd60789a52 x_refsource_MISC
- https://github.com/vercel/next.js/releases/tag/v15.5.27 x_refsource_MISC
- https://github.com/vercel/next.js/releases/tag/v16.3.8 x_refsource_MISC