Next.js versions from 16.3.0 to 16.3.7 warm use cache handlers using next/root-params and can leak their return value to pages with different root params. With Cache Components enabled (cacheComponents: true), a use cache function that calls another use cache function that reads a root param can be keyed incorrectly when the inner call is served from an existing entry: the enclosing functions cache key then omits that root param. The enclosing entry is written once and reused for all root param values, so a response for one root param value can serve content produced for a different value — whether the page is prerendered at build time or at runtime, or rendered dynamically. Shared cache headers let downstream caches redistribute the content further.
What values are leaked cannot be attacker controlled. Which values content is served depends only on which invocation wrote the entry first.
This has been patched in 16.3.8.
Weakness
The code uses a cache that contains sensitive information, but the cache can be read by an actor outside of the intended control sphere.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Next.js | Vercel | 16.3.0 (including) | 16.3.8 (excluding) |