Nuxt: Unauthenticated CPU exhaustion parsing and hashing the Nuxt island endpoint body before hash validation

NVD Description

### Impact The internal island renderer endpoint (`/__nuxt_island/...`) decodes and hashes attacker-controlled request input before it validates the URL-resident hash. An unauthenticated `POST /__nuxt_island/<name>_<anything>.json` with a large JSON body (for example ~4.6 MB / 150k keys) is fully read, `destr`-parsed, and run through `ohash` before the request is rejected with a 400. Because Nitro runs on a single event loop, this both wastes CPU on the doomed request and delays every concurrent request. A low request rate is enough to degrade or stall the server. No valid hash and no authentication are required. ### Patches Fixed in `nuxt@4.5.1` and `nuxt@3.21.10`. The island handler now enforces a raw body-size cap (`413`) and a JSON nesting-depth cap (`400`) before parsing or hashing, so oversized or deeply nested input is rejected cheaply. ### Workarounds Put a small request-body limit in front of `/__nuxt_island/` at your reverse proxy / edge (islands legitimately send only a compact props payload), or disable server components if unused.

Affected Packages (1)