# CVE-2026-85014: node-undici: undici's experimental WebSocketStream client crashes the whole Node.js process when a remote peer closes the TCP conn...

CVE-2026-85014 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-85014, released September 10, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-85014
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0037
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 4, 2026

## Description

undici's experimental WebSocketStream client crashes the whole Node.js process when a remote peer closes the TCP connection without a WebSocket close handshake. On an unclean close the internal socket-close handler calls abort on the writable stream unconditionally and discards the returned promise, but per the WHATWG Streams standard aborting a locked writable returns a promise that rejects with a TypeError. Because the application holds a writer on that writable, which is the only way to write, the rejection is never observed and Node's default unhandled-rejection behavior terminates the process. An untrusted server can therefore crash a client with a single abrupt disconnect, with no authentication and no application mistake. This affects undici versions from 7.0.0 up to 7.29.1 and from 8.0.0 up to 8.10.2. Users should upgrade to undici 7.29.1 or 8.10.2.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | node-undici Debian 14 | 8.10.2+dfsg+~cs3.2.2-1 | [DEBIAN-CVE-2026-85014](https://patchblox.com/security/data/fix/linux/debian-cve-2026-85014.md) | Sep 10, 2026 |
| Linux | pi-coding-agent opensuse-leap 16.0 | 1.0.4-bp160.1.1 | [OPENSUSE-SU-2026:22111-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22111-1.md) | Nov 7, 2026 |

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Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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