CVE-2026-21710

Node.js: Node.js: Denial of Service due to crafted HTTP header

Published Mar 30, 2026 · corrected/updated Aug 19, 2026 · Red Hat node.js · evidence confidence high

A flaw in Node.js HTTP request handling causes an uncaught when a request is received with a header named and the application accesses . When this occurs, resolves to rather than , causing to be called on a non-array. This exception is thrown synchronously inside a property getter and cannot be intercepted by event listeners, meaning it cannot be handled without wrapping every access in a . * This vulnerability affects all Node.js HTTP servers on **20.x, 22.x, 24.x, and v25.x**

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2026-21710 is a high public vulnerability record for Red Hat node.js. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether Red Hat node.js is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: nodejs/node.js; redhat/enterprise linux (10.0); redhat/enterprise linux (8.0); redhat/enterprise linux (9.0). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 7.5, EPSS 25.0%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-770, CWE-843. Sources contributing to this record: csaf, csaf, cve_org, epss. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

Exploitation evidence
Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

Mar 30, 2026 · NIST NVD
Detected
A flaw in Node.js HTTP request handling causes an uncaught when a request is received with a header named and the application accesses . When this occurs, resolves to rather than , causing to be called on a non-array. This exception is thrown synchronously inside a property getter and cannot be intercepted by event listeners, meaning it cannot be handled without wrapping every access in a . * This
Aug 19, 2026 · NIST NVD
Updated
A flaw in Node.js HTTP request handling causes an uncaught when a request is received with a header named and the application accesses . When this occurs, resolves to rather than , causing to be called on a non-array. This exception is thrown synchronously inside a property getter and cannot be intercepted by event listeners, meaning it cannot be handled without wrapping every access in a . * This

Affected

cpe nodejs/node.jsversion unspecified
cpe redhat/enterprise linux10.0
cpe redhat/enterprise linux8.0
cpe redhat/enterprise linux9.0
cpe redhat/enterprise linux eus9.4

Sources

CSAF AdvisoriesVendor advisoryRHSA-2026:9711:CVE-2026-21710
A flaw was found in Node.js. A remote attacker can exploit this vulnerability by sending a specially crafted HTTP request that includes a header named . When a Node.js application processes this request and attempts to access distinct headers, it encounters an unhandled error, le
security.access.redhat.com
CSAF AdvisoriesVendor advisoryRHSA-2026:9874:CVE-2026-21710
A flaw was found in Node.js. A remote attacker can exploit this vulnerability by sending a specially crafted HTTP request that includes a header named . When a Node.js application processes this request and attempts to access distinct headers, it encounters an unhandled error, le
security.access.redhat.com
CVE.orgVulnerability recordCVE-2026-21710
Official CVE identifier
cve.org
FIRST EPSSExploitation probabilityCVE-2026-21710
30-day exploitation probability 25.0%
first.org
NIST NVDVulnerability recordCVE-2026-21710
A flaw in Node.js HTTP request handling causes an uncaught when a request is received with a header named and the application accesses . When this occurs, resolves to rather than , c
nvd.nist.gov