CVE-2026-21710
Description
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**
Severity
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HAffected Products
| Vendor | Product | Affected versions |
|---|---|---|
| nodejs | node | 20.20.1 to 20.20.1 22.22.1 to 22.22.1 24.14.0 to 24.14.0 25.8.1 to 25.8.1 4.0 to <4.* 5.0 to <5.* 6.0 to <6.* 7.0 to <7.* 8.0 to <8.* 9.0 to <9.* 10.0 to <10.* 11.0 to <11.* 12.0 to <12.* 13.0 to <13.* 14.0 to <14.* 15.0 to <15.* 16.0 to <16.* 17.0 to <17.* 18.0 to <18.* 19.0 to <19.* |
References
1 LinksRecord Details
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