CVE-2026-126051
Description
A flaw was found in Node.js. A remote, unauthenticated attacker can exploit this vulnerability to cause a denial of service (DoS) by terminating the server process. When a Transport Layer Security (TLS) server is configured with certain handshake callback hooks, it fails to handle situations where the underlying network connection is closed before the deferred callback executes. By sending a specially crafted TLS handshake request immediately followed by a connection closure, an attacker triggers an unhandled exception that crashes the application.
Statement
Red Hat Product Security rates this vulnerability as an Important severity flaw because an unauthenticated remote attacker can terminate the Node.js process, leading to a complete denial of service. The issue specifically impacts applications where the Node.js server handles TLS handshakes directly and registers dynamic context or certificate hooks, such as SNI or session resumption callbacks. Deployments where TLS traffic is terminated upstream by a reverse proxy, load balancer, or OpenShift ingress controller do not execute the vulnerable handshake path in Node.js and are not exposed.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | N/A | 7.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability,Confidentiality
Technical Impact: DoS: Crash, Exit, or Restart; Read Application Data
An uncaught exception could cause the system to be placed in a state that could lead to a crash, exposure of sensitive information, or other unintended behaviors.
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