CVE-2026-21710

Advisory lineage Upstream: 0 Downstream: 28
Awaiting Analysis
Published: 30 Mar 2026, 19:07
Last modified:15 Jul 2026, 01:19

Vulnerability Summary

Overall Risk (default)
medium
35/100
CVSS Score
7.5 HIGH
v3.1 (cve.org)
EPSS Score
26.36% HIGH
26% probability +13.29%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

30 Mar 2026, 19:07
Published
Vulnerability first disclosed
15 Jul 2026, 01:19
Last Modified
Vulnerability information updated

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 Metrics

  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
  • v3.0•HIGH•Score: 7.5CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 26.36%• Percentile: 98%

Techniques & Countermeasures

  • CWE-770•Allocation of Resources Without Limits or Throttling

    The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

  • CWE-843•Access of Resource Using Incompatible Type ('Type Confusion')

    The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.

Affected Systems

  • nodejs•node

    20.20.1 | 22.22.1 | 24.14.0 | 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.*

References (16)