CVE-2026-21710
HIGH
7,5
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: none
Integrity: none
Availability: high
Description
AI Translation Available
A flaw in Node.js HTTP request handling causes an uncaught `TypeError` when a request is received with a header named `__proto__` and the application accesses `req.headersDistinct`.
When this occurs, `dest['__proto__']` resolves to `Object.prototype` rather than `undefined`, causing `.push()` to be called on a non-array. This exception is thrown synchronously inside a property getter and cannot be intercepted by `error` event listeners, meaning it cannot be handled without wrapping every `req.headersDistinct` access in a `try/catch`.
* This vulnerability affects all Node.js HTTP servers on **20.x, 22.x, 24.x, and v25.x**
https://nodejs.org/en/blog/vulnerability/march-2026-security-releases