ALPINE-CVE-2026-21710

ALPINE-CVE-2026-21710

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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**

CVSS 7.5 · High · Fix available

Published

2026-03-30T20:16:18.210Z

Updated

2026-10-01T02:17:49.204680831Z

Stack: system

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