Summary
Sending a GET or HEAD request with a body crashes SvelteKit
In SvelteKit 2 sending a GET request with a body eg {} to a SvelteKit app in preview or with adapter-node throws Request with GET/HEAD method cannot have body. and crashes the app.
node:internal/deps/undici/undici:6066
throw new TypeError("Request with GET/HEAD method cannot have body.");
^
TypeError: Request with GET/HEAD method cannot have body.
at new Request (node:internal/deps/undici/undici:6066:17)
at getRequest (file:///C:/Users/admin/Desktop/reproduction/node_modules/@sveltejs/kit/src/exports/node/index.js:107:9)
at file:///C:/Users/admin/Desktop/reproduction/node_modules/@sveltejs/kit/src/exports/vite/preview/index.js:181:26
at call (file:///C:/Users/admin/Desktop/reproduction/node_modules/vite/dist/node/chunks/dep-9A4-l-43.js:44795:7)
at next (file:///C:/Users/admin/Desktop/reproduction/node_modules/vite/dist/node/chunks/dep-9A4-l-43.js:44739:5)
at file:///C:/Users/admin/Desktop/reproduction/node_modules/@sveltejs/kit/src/exports/vite/preview/index.js:172:6
at call (file:///C:/Users/admin/Desktop/reproduction/node_modules/vite/dist/node/chunks/dep-9A4-l-43.js:44795:7)
at next (file:///C:/Users/admin/Desktop/reproduction/node_modules/vite/dist/node/chunks/dep-9A4-l-43.js:44739:5)
at file:///C:/Users/admin/Desktop/reproduction/node_modules/@sveltejs/kit/src/exports/vite/preview/index.js:211:27
at call (file:///C:/Users/admin/Desktop/reproduction/node_modules/vite/dist/node/chunks/dep-9A4-l-43.js:44795:7)
Node.js v20.11.0
TRACE requests will also cause the app to crash. Prerendered pages and SvelteKit 1 apps are not affected.
PoC
First do a fresh install of SvelteKit 2 with the example app. Typescript.
npm run buildnpm run preview- Go to http://localhost:4173 (works)
- curl -X GET -d "{}" http://localhost:4173/bye
- Application crashes and http://localhost:4173 is down
Impact
Denial of Service for apps using adapter-node
The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.
CVE-2024-23641 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 (2.4.3, 2.1.2, 3.0.3, 4.0.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
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.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
@sveltejs/kit to 2.4.3 or later; @sveltejs/adapter-node to 2.1.2 or later; @sveltejs/adapter-node to 3.0.3 or later; @sveltejs/adapter-node to 4.0.1 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2024-23641? CVE-2024-23641 is a high-severity improper input validation vulnerability in @sveltejs/kit (npm), affecting versions >= 2.0.0, < 2.4.3. It is fixed in 2.4.3, 2.1.2, 3.0.3, 4.0.1. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
- How severe is CVE-2024-23641? CVE-2024-23641 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.
- Which packages are affected by CVE-2024-23641?
@sveltejs/kit(npm) (versions >= 2.0.0, < 2.4.3)@sveltejs/adapter-node(npm) (versions >= 2.0.0, < 2.1.2)
- Is there a fix for CVE-2024-23641? Yes. CVE-2024-23641 is fixed in 2.4.3, 2.1.2, 3.0.3, 4.0.1. Upgrade to this version or later.
- Is CVE-2024-23641 exploitable, and should I be worried? Whether CVE-2024-23641 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
- What actually determines whether CVE-2024-23641 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.
- How do I fix CVE-2024-23641?
- Upgrade
@sveltejs/kitto 2.4.3 or later - Upgrade
@sveltejs/adapter-nodeto 2.1.2 or later - Upgrade
@sveltejs/adapter-nodeto 3.0.3 or later - Upgrade
@sveltejs/adapter-nodeto 4.0.1 or later
- Upgrade