Node undici: undici's experimental WebSocketStream client crashes the whole Node.js process when a remote peer closes the TCP connection without a WebSocket… (CVE-2026-85014)
Description
A denial of service vulnerability exists in the undici library's WebSocketStream API for Node.js. When a remote peer closes the TCP connection abruptly without performing a proper WebSocket close handshake, the client process crashes. This is due to an unhandled promise rejection triggered by aborting a writable stream while a writer lock is held. The vulnerability affects undici versions from 7.0.0 up to but not including 7.29.1, and from 8.0.0 up to but not including 8.10.2. Patches are available in versions 7.29.1 and 8.10.2. No workaround is currently available.
CVSS v3.1
Score 7.5high
Affected software
pkg:deb/ubuntu/node-undici?arch=source&distro=noblepkg:deb/ubuntu/node-undici?arch=source&distro=resolutepkg:deb/ubuntu/node-undici?arch=source&distro=stonkingRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in undici's WebSocketStream API causes the Node.js process to crash when a remote WebSocket server closes the TCP connection abruptly without a proper close handshake. Internally, the socket-close handler aborts a writable stream while a writer lock is held, leading to an unhandled promise rejection that terminates the process. This denial of service affects undici versions >=7.0.0 <7.29.1 and >=8.0.0 <8.10.2. The issue can be triggered by a malicious or compromised WebSocket server. Fixed versions 7.29.1 and 8.10.2 address the problem.
Potential Impact
Successful exploitation causes a denial of service by crashing the Node.js process using the undici WebSocketStream client. This results in service interruption but does not impact confidentiality or integrity. The vulnerability can be triggered remotely by a malicious or compromised WebSocket server.
Mitigation Recommendations
Patches are available in undici versions 7.29.1 and 8.10.2. Users should upgrade to these versions or later to remediate the vulnerability. No workaround is currently available.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-85014
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:24.04:LTS","Ubuntu:26.04:LTS"]
- Cvss Version
- 3.1
Threat ID: 6a9ee1aeacd9273b49e69c05
Added to database: 09/07/2026, 16:09:18 UTC
Last enriched: 10/18/2026, 02:25:02 UTC
Last updated: 10/22/2026, 13:15:24 UTC
Views: 82
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