CVE-2026-85014

Summary

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.

Affected Software

VendorProductVersion RangeStatus
undiciundici7.0.0 < 7.29.1affected
undiciundici7.29.1unaffected
undiciundici8.0.0 < 8.10.2affected
undiciundici8.10.2unaffected

Weaknesses

  • CWE-248: CWE-248: Uncaught Exception
  • CWE-754: CWE-754: Improper Check for Unusual or Exceptional Conditions

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References