CVE-2026-21710 remediation guide

nodejs node, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support

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...

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Research in progress

A verified fixed-version field is not available. Use the linked NVD and supporting references, then confirm the vendor-supported path before changing production systems.

Productnodejs node, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support

Affected versions>= 20.20.1 <= 20.20.1, >= 22.22.1 <= 22.22.1, >= 24.14.0 <= 24.14.0, >= 25.8.1 <= 25.8.1, >= 4.0 < 4.*, >= 5.0 < 5.*, >= 6.0 < 6.*, >= 7.0 < 7.*, >= 8.0 < 8.*, >= 9.0 < 9.*, >= 10.0 < 10.*, >= 11.0 < 11.*, >= 12.0 < 12.*, >= 13.0 < 13.*, >= 14.0 < 14.*, >= 15.0 < 15.*, >= 16.0 < 16.*, >= 17.0 < 17.*, >= 18.0 < 18.*, >= 19.0 < 19.*

Fixed versionsNo verified fixed-version field is available yet

Priority basisPriority · CVSS 7.5 · EPSS 26.4%

Identify the affected asset

Confirm whether nodejs node, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support is installed, record the deployed version and installation path, and identify exposed interfaces.

Record the product name, package or appliance identifier, and installed version.
Identify internet-facing, administrative, API, and internal access paths.
Preserve the pre-change configuration and relevant service logs.

Validate the affected-version match

Compare the deployed version with the affected range: >= 20.20.1 <= 20.20.1, >= 22.22.1 <= 22.22.1, >= 24.14.0 <= 24.14.0, >= 25.8.1 <= 25.8.1, >= 4.0 < 4.*, >= 5.0 < 5.*, >= 6.0 < 6.*, >= 7.0 < 7.*, >= 8.0 < 8.*, >= 9.0 < 9.*, >= 10.0 < 10.*, >= 11.0 < 11.*, >= 12.0 < 12.*, >= 13.0 < 13.*, >= 14.0 < 14.*, >= 15.0 < 15.*, >= 16.0 < 16.*, >= 17.0 < 17.*, >= 18.0 < 18.*, >= 19.0 < 19.*. Treat incomplete inventory results as unresolved.

Prioritize with independent signals

FIRST EPSS indicates an elevated probability of exploitation. Combine this signal with asset criticality, exposure, compensating controls, and business impact.

Apply supported remediation

Follow the vendor advisory or supported update path. Current fixed-version status: No verified fixed-version field is available yet. Preserve configuration and rollback material before change.

Verify the result

Confirm the resulting version, service health, authentication and access paths, monitoring coverage, and relevant security logs.

Confirm the expected version and package state.
Run a functional health check for critical service paths.
Review authentication, error, application, and security monitoring logs.
Reassess exposure if the supported fix cannot be applied.

Operational boundary

This page does not replace the vendor advisory, support contract, change-management process, or recovery plan. Do not infer that an asset is unaffected from an incomplete inventory query or a missing fixed-version field.