CVE-2026-85024Network attack vectorHinoki check available

Process crash via orphaned zlib error event

Published Sep 4, 2026 · Updated Sep 4, 2026

Uncaught exception in Undici's WebSocket client allows remote attackers to crash the Node.js process through malformed compressed messages. The size-limit cleanup in lib/web/websocket/permessage-deflate.js calls removeAllListeners() on a live InflateRaw stream, stripping its error handler. Reachability requires a connection to an attacker-controlled or compromised WebSocket endpoint; one message terminates the process, and reconnects can repeat the crash.

CVSS severity5.9
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Uncaught exception in Undici's WebSocket client allows remote attackers to crash the Node.js process through malformed compressed messages. The size-limit cleanup in lib/web/websocket/permessage-deflate.js calls removeAllListeners() on a live InflateRaw stream, stripping its error handler. Reachability requires a connection to an attacker-controlled or compromised WebSocket endpoint; one message terminates the process, and reconnects can repeat the crash.

The record

CVE
CVE-2026-85024
Published
Sep 4, 2026
Updated
Sep 4, 2026
Vendor
Node.js
Product
Undici
Classifications
CWE-248, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.25.0 <6.28.1
  2. Affected versionversion=7.28.0 <7.29.1
  3. Affected versionversion=8.1.0 <8.10.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Node.js · Undiciversion=6.25.0 <6.28.1; version=7.28.0 <7.29.1; version=8.1.0 <8.10.2

Published CVSS scores

5.9GitHubCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-248Uncaught Exception
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo