UpHeron
All vulnerabilities

Servers and applications

CVE-2026-21637

Incomplete fix for CVE-2026-21637: `loadSNI()` in `_tls_wrap.js` lacks `try`/`catch` leading to Remote DoS

Severity
High 7.5
Published
20 Jan 2026
Last changed
17 Jun 2026
Added to UpHeron
21 Oct 2026
Fixed in
22.22.0, 22.22.2, 24.13.0, 24.14.1, 25.3.0, 25.8.2
Sources
NVD, nodejs

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.…

Affected software

SoftwareAffected versions
Node.jsServers and applications · cpe:a:nodejs:node.js
  • From 25.0.0 before 25.3.0
  • From 25.0.0 before 25.8.2
  • From 24.0.0 before 24.13.0
  • From 24.0.0 before 24.14.1
All 8 release lines
  • From 4.0.0 before 20.20.0
  • From 20.0.0 before 20.20.2
  • From 22.0.0 before 22.22.2
  • From 22.0.0 before 22.22.0
  • From 24.0.0 before 24.14.1
  • From 24.0.0 before 24.13.0
  • From 25.0.0 before 25.8.2
  • From 25.0.0 before 25.3.0

References

  • NVD https://nvd.nist.gov/vuln/detail/CVE-2026-21637
  • CVE.org https://www.cve.org/CVERecord?id=CVE-2026-21637
  • Node.js security release https://nodejs.org/en/blog/vulnerability/march-2026-security-releases