CVE-2026-21637

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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://nodejs.org/en/blog/vulnerability/december-2025-security-releases	Release Notes Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:nodejs:node.js:::::-:::*
	cpe:2.3:a:nodejs:node.js:::::-:::*
	cpe:2.3:a:nodejs:node.js:::::-:::*
	cpe:2.3:a:nodejs:node.js:::::-:::*

History

No history.

Information

Published : 2026-01-20 21:16

Updated : 2026-01-30 20:18

NVD link : CVE-2026-21637

Mitre link : CVE-2026-21637

CVE.ORG link : CVE-2026-21637

JSON object : View

Products Affected

nodejs

node.js

CWE

CWE-400

Uncontrolled Resource Consumption

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