Nuxt: Unauthenticated CPU exhaustion parsing and hashing the Nuxt island endpoint body before hash validation
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 software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | nuxt | >= 4.0.0, < 4.5.1, >= 3.1.0, < 3.21.10 | 4.5.1, 3.21.10 |
References
- https://github.com/nuxt/nuxt/security/advisories/GHSA-9pgf-384g-p7mv
- https://github.com/nuxt/nuxt/commit/4e35ae9babd94be53246e31200232d48438bb34e
- https://github.com/nuxt/nuxt/commit/668cdfdfda41849ed11c1ee5e2067a11fc103b22
- https://github.com/nuxt/nuxt
- https://github.com/nuxt/nuxt/releases/tag/v3.21.10
- https://github.com/nuxt/nuxt/releases/tag/v4.5.1
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-407, CWE-770- Platform
- npm
- Package
nuxt- Disclosed
- 05.08.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-9pgf-384g-p7mv - CC BY 4.0
Vulnerability history: nuxt
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 21
- First → latest
- 06.2023 08.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 2
- High 7
- Medium 8
- Low 4
Disclosures per year
- 2023: 1
- 2024: 2
- 2025: 2
- 2026: 16
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Nuxt: Unauthenticated CPU exhaustion parsing and hashing the Nuxt island endpoint body before hash validation this entry
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