- High 7.5
CVE-2026-21710
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 **…
Scores
The facts
- Published
- 30 March 2026
- Last changed
- 19 August 2026
- NVD status
- Analyzed
- Severity
- High, CVSS 7.5 out of 10 (version 3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- Affects
- nodejs node.js
- redhat enterprise linux
- redhat enterprise linux eus
- Known exploited
- Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
- EPSS
- 25.0% chance of exploitation activity in the next 30 days (percentile 98).
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