CVE-2026-40073

CVE-2026-40073 is a high-severity allocation of resources without limits or throttling vulnerability in @sveltejs/kit (npm), affecting versions <= 2.57.0. It is fixed in 2.57.1.

Summary

Under certain circumstances, requests could bypass the BODY_SIZE_LIMIT on SvelteKit applications running with adapter-node. This bypass does not affect body size limits at other layers of the application stack, so limits enforced in the WAF, gateway, or at the platform level are unaffected.

Impact

The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.

Affected versions

@sveltejs/kit (<= 2.57.0)

Security releases

@sveltejs/kit → 2.57.1 (npm)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

See it in your environment

Remediation advice

Upgrade @sveltejs/kit to 2.57.1 or later to resolve this vulnerability.

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

  1. What is CVE-2026-40073? CVE-2026-40073 is a high-severity allocation of resources without limits or throttling vulnerability in @sveltejs/kit (npm), affecting versions <= 2.57.0. It is fixed in 2.57.1. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.
  2. Which versions of @sveltejs/kit are affected by CVE-2026-40073? @sveltejs/kit (npm) versions <= 2.57.0 is affected.
  3. Is there a fix for CVE-2026-40073? Yes. CVE-2026-40073 is fixed in 2.57.1. Upgrade to this version or later.
  4. Is CVE-2026-40073 exploitable, and should I be worried? Whether CVE-2026-40073 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
  5. What actually determines whether CVE-2026-40073 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.
  6. How do I fix CVE-2026-40073? Upgrade @sveltejs/kit to 2.57.1 or later.

Other vulnerabilities in @sveltejs/kit

CVE-2026-40074CVE-2026-40073CVE-2026-22803CVE-2025-67647CVE-2024-53261

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