CVE-2026-21710
Published: Mar 30, 2026
Modified: Mar 31, 2026
CVSS v3.0
7.5
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**
| Vendor | Product | Versions |
|---|---|---|
nodejs | node | affected 20.20.1 - <= 20.20.1affected 22.22.1 - <= 22.22.1affected 24.14.0 - <= 24.14.0affected 25.8.1 - <= 25.8.1affected 4.0 - < 4.*+15 more versions |
CVSS v3.0 Details
CVSS v3.0 Vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
Security Training
Train your team to recognize and prevent security threats with our comprehensive security awareness program.
Start TrainingVulnerability Scanning
Discover vulnerabilities in your applications and infrastructure before attackers do.
Scan Now