vulntracker.iovulntracker.io
© 2026 vulntracker.io

CVE-2026-21637

HIGH
7.5
CVSS Score
Published: January 20, 2026 at 08:41 PM UTC
Updated: June 17, 2026 at 10:18 AM UTC
1 product affected across 1 vendorNode.js

Using node by nodejs?

Get instant alerts when new vulnerabilities affect node - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Start FreeSign In
Severity
HIGH7.5
Exploit prediction
EPSS 1%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Node.js· Node.js
95%
10.0 ≤ v < 10.*11.0 ≤ v < 11.*12.0 ≤ v < 12.*13.0 ≤ v < 13.*14.0 ≤ v < 14.*15.0 ≤ v < 15.*16.0 ≤ v < 16.*17.0 ≤ v < 17.*18.0 ≤ v < 18.*22.0.0 ≤ v < 22.22.024.0.0 ≤ v < 24.13.025.0.0 ≤ v < 25.3.04.0 ≤ v < 4.*4.0.0 ≤ v < 20.20.05.0 ≤ v < 5.*6.0 ≤ v < 6.*7.0 ≤ v < 7.*8.0 ≤ v < 8.*9.0 ≤ v < 9.*10.011.012.013.014.015.016.017.018.020.19.622.21.124.12.025.2.14.05.06.07.08.09.0
Affected range stops below 10.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 11.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 12.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 13.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 14.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 15.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 16.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 17.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 18.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 5.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 6.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 7.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 8.*, so it looks safe — our inference, not a vendor statement
Affected range stops below 9.*, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (1)

Release NotesVendor Advisory
Source: cverecord
https://nodejs.org/en/blog/vulnerability/december-2025-security-releases

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGH[email protected]
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-400

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create accountSign in
Free plan, no card