A flaw in Node.js TLS error handling allows remote attackers… (CVE-2026-21637)

Original description

The description as published by the source.

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.

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Affected packages

Bitnami node

[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"20.20.0"},{"introduced":"21.0.0"},{"fixed":"22.22.0"},{"introduced":"23.0.0"},{"fixed":"24.13.0"},{"introduced":"25.0.0"},{"fixed":"25.3.0"}]}]

Bitnami node-min

[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"20.20.0"},{"introduced":"21.0.0"},{"fixed":"22.22.0"},{"introduced":"23.0.0"},{"fixed":"24.13.0"},{"introduced":"25.0.0"},{"fixed":"25.3.0"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

Alpine Linux ALPINE-CVE-2026-21637 nodejs Fixed in: 22.22.2-r0
Debian DEBIAN-CVE-2026-21637 nodejs Fixed in: 12.22.12~dfsg-1~deb11u8
Ubuntu UBUNTU-CVE-2026-21637 nodejs

References

advisory nodejs.org
web nvd.nist.gov