GHSA-rx4f-c7p8-82vq: undici (CVE-2026-85014)

Package	Ecosystem	Affected	Fixed in
undici	npm	>=7.0.0, <7.29.1 \|\| >=8.0.0, <8.10.2	7.29.1, 8.10.2

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

The undici npm package, versions 7.0.0 up to 7.29.1 and 8.0.0 up to 8.10.2, has a flaw in its WebSocketStream API that can crash the client process. When a WebSocket connection closes abruptly without a close handshake, an unobserved promise rejection occurs, which under Node.js defaults terminates the process. A malicious or compromised WebSocket server can trigger this with a single connection teardown, and the issue affects applications that write through a writer. Upgrade to undici 7.29.1 or 8.10.2; no workaround is listed.

Written 31 Oct 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
5.9	Medium	3.1	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H	CNA (openjs)

CISA KEV Not listed.
EPSS 0.0037, the 30th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 13:34 UTC First seen by agentprime
31 Oct 2026, 13:34 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.