Allocation of Resources Without Limits or Throttling in undici - CVE-2026-12151
Published: June 17, 2026
Vulnerability identifier: #VU134753
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-12151
CWE-ID: CWE-770
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Node.js
Affected software:
undici
undici
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to allocation of resources without limits or throttling in the WebSocket client message fragmentation handling when processing fragmented WebSocket messages from a server. A remote attacker can send many small or empty continuation frames to cause a denial of service.
Exploitation requires the application to connect to an attacker-controlled or compromised WebSocket endpoint using the WebSocket client or the WebSocketStream API.
How to mitigate CVE-2026-12151
Install security update from vendor's website.