Description

A flaw in Node.js TLS error handling allows remote attackers to crash or exhaust resources of a TLS server when `pskCallback` or `ALPNCallback` are in use. Synchronous exceptions thrown during these callbacks bypass standard TLS error handling paths (tlsClientError and error), causing either immediate process termination or silent file descriptor leaks that eventually lead to denial of service. Because these callbacks process attacker-controlled input during the TLS handshake, a remote client can repeatedly trigger the issue. This vulnerability affects TLS servers using PSK or ALPN callbacks across Node.js versions where these callbacks throw without being safely wrapped.

INFO

Published Date :

2026-01-20T20:41:55.352Z

Last Modified :

2026-01-21T20:22:51.033Z

Source :

hackerone
AFFECTED PRODUCTS

The following products are affected by CVE-2026-21637 vulnerability.

Vendors Products
Nodejs
  • Node.js
  • Nodejs
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-21637.

CVSS Vulnerability Scoring System

Detailed values of each vector for above chart.
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Detailed values of each vector for above chart.
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact