Vulnerability 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**
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Nodejs | Node.Js | <= 20.20.1 |
| Redhat | Enterprise Linux | 8.0 |
| Redhat | Enterprise Linux Eus | 9.4 |
Related Weaknesses (CWE)
References
- https://nodejs.org/en/blog/vulnerability/march-2026-security-releasesVendor Advisory
- https://access.redhat.com/errata/RHSA-2026:7080Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7123Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7302Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7310Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7350Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7670Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7675Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7896Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:7983Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:8339Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:9711Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:9874Third Party Advisory
- https://access.redhat.com/security/cve/CVE-2026-21710Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2453151Issue Tracking
FAQ
What is CVE-2026-21710?
CVE-2026-21710 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 occur...
How severe is CVE-2026-21710?
CVE-2026-21710 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-21710?
Check the references section above for vendor advisories and patch information. Affected products include: Nodejs Node.Js, Redhat Enterprise Linux, Redhat Enterprise Linux Eus.