CVE-2026-21710 Affecting nodejs:20/nodejs-nodemon package, versions <0:3.0.1-1.module_el8.10.0+3982+85c136aa


Severity

Recommended
high

Based on AlmaLinux security rating.

Threat Intelligence

EPSS
0.02% (6th percentile)

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  • Snyk IDSNYK-ALMALINUX8-NODEJS-16094773
  • published17 Apr 2026
  • disclosed9 Apr 2026

Introduced: 9 Apr 2026

NewCVE-2026-21710  (opens in a new tab)

How to fix?

Upgrade AlmaLinux:8 nodejs:20/nodejs-nodemon to version 0:3.0.1-1.module_el8.10.0+3982+85c136aa or higher.
This issue was patched in ALSA-2026:8339.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nodejs:20/nodejs-nodemon package and not the nodejs:20/nodejs-nodemon package as distributed by AlmaLinux. See How to fix? for AlmaLinux:8 relevant fixed versions and status.

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[&#34;__proto__&#34;] 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 Base Scores

version 3.1