# CVE-2026-71321 — nuxt

> As of 2026-08-06, CVE-2026-71321 is a HIGH-severity vulnerability in nuxt, CVSS v3.1 7.5, EPSS 0.4% (34.8th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-71321 as of 2026-08-06; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-08-06

## What is CVE-2026-71321?

Nuxt is an open-source web development framework for Vue.js. From 3.1.0 until 3.21.10 and 4.5.1, the internal island renderer endpoint `/__nuxt_island/...` decodes and hashes attacker-controlled JSON body input with destr and ohash before validating the URL-resident hash. An unauthenticated `POST /__nuxt_island/_.json` with a large JSON body is fully read, parsed, hashed, and then rejected, which wastes CPU on Nitro single event loop and delays concurrent requests. No valid hash and no authentication are required. This issue is fixed in 3.21.10 and 4.5.1.

The record classifies CVE-2026-71321 under weakness classes [CWE-407](https://cwe.mitre.org/data/definitions/407.html), [CWE-770](https://intel.threadlinqs.com/cwe/CWE-770). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 61 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.5 — HIGH (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **EPSS (FIRST):** 0.4% probability of exploitation in the next 30 days, higher than 34.8% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 5.1/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-05, last modified 2026-08-06

## Is CVE-2026-71321 being exploited?

It currently carries a trending score of 38 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [nuxt](https://intel.threadlinqs.com/vendors/nuxt): nuxt

Affected software packages:

- `npm:nuxt` — patched in 4.5.1
- `npm:nuxt` — patched in 3.21.10

## How to fix CVE-2026-71321

Fixed versions are recorded for 2 packages: npm:nuxt 4.5.1, npm:nuxt 3.21.10. No vendor patch reference has been recorded for CVE-2026-71321 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-71321

No threat campaign in the Threadlinqs corpus currently references CVE-2026-71321, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-08-06.

**Vendor advisory and patch**

- [github.com](https://github.com/nuxt/nuxt/security/advisories/GHSA-9pgf-384g-p7mv)

**Other references**

- [github.com](https://github.com/nuxt/nuxt/commit/4e35ae9babd94be53246e31200232d48438bb34e)
- [github.com (668cdfdfda41849ed11c1ee5e2067a11fc103b22)](https://github.com/nuxt/nuxt/commit/668cdfdfda41849ed11c1ee5e2067a11fc103b22)
- [github.com (v3.21)](https://github.com/nuxt/nuxt/releases/tag/v3.21.10)
- [github.com (v4.5)](https://github.com/nuxt/nuxt/releases/tag/v4.5.1)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-71321
Full detection coverage and IOCs for threats exploiting CVE-2026-71321 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp