CVE-2026-21637

Name of the Vulnerable Software and Affected Versions Node.js versions (affected versions not specified)

Description A flaw in Node.js TLS error handling can allow 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, potentially leading to denial of service. Because these callbacks process attacker-controlled input during the TLS handshake, a remote client can repeatedly trigger the issue. The issue is related to incorrect cleanup or release of resources within the pskCallback() and ALPNCallback() functions.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.