CVE-2026-71314

Nuxt: Unauthenticated out-of-memory crash via unbounded v-for expansion in island rendering

Workarounds

Avoid v-for directly over an unclamped prop in server components, or clamp the count in the component (v-for="n in Math.min(count, 1000)"). A body-size limit in front of /__nuxt_island/ only mitigates array-shaped inputs, not the integer-amplification case.

References

• Bound helper: packages/nuxt/src/app/components/vfor.ts
• Transform: packages/nuxt/src/components/plugins/islands-transform.ts
• Slot helper: packages/nuxt/src/app/components/utils.ts (vforToArray)

An unauthenticated attacker can crash a Nuxt server that renders any island / server component containing a v-for over a prop (for example v-for="n in count" or a <slot v-for>). Because the island URL hash is a non-secret digest of the request, the attacker can compute a valid hash for arbitrary props and send the iterated prop as a large integer. The server then expands the v-for to that many nodes during SSR, allocating memory proportional to the attacker's number. Reporter figures: count=8000000 produced a 142.9 MB response; count=40000000 (and items=4000000 on a slot list) produced an out-of-memory crash of the worker from a single ~130-byte request. Both the plain v-for path (Vue's ssrRenderList) and the slot path (vforToArray) are affected.

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2026-71314 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (4.5.1, 3.21.10); upgrading removes the vulnerable code path.

Kodem intelligence

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Fixed in [email protected] and [email protected]. Island/server-component v-for sources are now clamped to a maximum iteration count (MAX_VFOR_LENGTH = 100000) at the render boundary, covering the plain path, the <slot v-for> element, and the vforToArray slot-props helper. Combined with the body-size cap (GHSA-9pgf-384g-p7mv), a single island render can no longer allocate without bound regardless of which v-for path is used or whether the prop arrives as an integer or an array.

1. What is CVE-2026-71314? CVE-2026-71314 is a high-severity uncontrolled resource consumption vulnerability in nuxt (npm), affecting versions >= 4.0.0, < 4.5.1. It is fixed in 4.5.1, 3.21.10. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is CVE-2026-71314? CVE-2026-71314 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of nuxt are affected by CVE-2026-71314? nuxt (npm) versions >= 4.0.0, < 4.5.1 is affected.
4. Is there a fix for CVE-2026-71314? Yes. CVE-2026-71314 is fixed in 4.5.1, 3.21.10. Upgrade to this version or later.
5. Is CVE-2026-71314 exploitable, and should I be worried? Whether CVE-2026-71314 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2026-71314 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2026-71314?
   • Upgrade nuxt to 4.5.1 or later
   • Upgrade nuxt to 3.21.10 or later

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