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Vulnerabilities

Vulnerability · CVE-2026-21710

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

Published Mar 30, 2026 · catalog updated Aug 19, 2026 · Red Hat

Check this week

CVE-2026-21710 is not in CISA KEV. FIRST estimates a 25.04% chance of exploitation in the next 30 days. Check whether you run Red Hat.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
25.04%
Remediation
Advisory link
Affected products
cpe nodejs/node.js · cpe redhat/enterprise linux · cpe redhat/enterprise linux eus

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**

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • 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

How to fix CVE-2026-21710

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2026-21710 is not in CISA KEV. FIRST estimates a 25.04% chance of exploitation in the next 30 days. Check whether you run Red Hat.

Which versions are affected?

Compare what you have installed with redhat/enterprise linux 10.0; redhat/enterprise linux 8.0; redhat/enterprise linux 9.0; redhat/enterprise linux eus 9.4. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-770: Allocation of Resources Without Limits or Throttling; CWE-843: Access of Resource Using Incompatible Type (Type Confusion). EPSS 25.04%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

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.

  1. 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

  2. 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

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

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.