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Medium 5.9Published Sep 4, 2026

CVE-2026-85014undici vulnerable to Denial of Service via WebSocketStream unclean close

Updated under an hour ago ()

Does this affect you?

It affects undici and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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.

CVSS
5.9 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE)
CWE-248, CWE-754
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
openjs
NVD analysis
Analyzed
Record last updated
Sep 4, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
undici undici
undici:undici (from the name)
from 7.0.0 before 7.29.1; 7.29.1 not affected; from 8.0.0 before 8.10.2; 8.10.2 not affected
CNA record
nodejs undici
nodejs:undici
from 7.0.0 before 7.29.1; from 8.0.0 before 8.10.2
NVD

References

  • vendor-advisory
  • third-party-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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