CVE-2026-85024

undici bundles a WebSocket client whose permessage-deflate size-limit cleanup removes all listeners from the internal zlib inflate stream, including its error listener, while that stream can still emit. When a remote peer sends a compressed payload that crosses the built-in 128 MiB decompressed-payload limit and then contains a malformed DEFLATE byte, the inflate stream emits a data error with no listener attached, which Node.js treats as a fatal unhandled error and terminates the entire process. Exploitation is remote and unauthenticated, requires no application mistake, and is asymmetric, since roughly 130 KB on the wire expands past the limit and crashes the process, and reconnecting can repeat the crash. This affects undici versions from 6.25.0 up to 6.28.1, from 7.28.0 up to 7.29.1, and from 8.1.0 up to 8.10.2. Users should upgrade to undici 6.28.1, 7.29.1, or 8.10.2.

CVSS v3 5.9 MEDIUM

5.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.2 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://cna.openjsf.org/security-advisories.html	Vendor Advisory
https://github.com/nodejs/undici/security/advisories/GHSA-3wwx-pv8p-q78v	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:nodejs:undici::::::node.js::*
	cpe:2.3:a:nodejs:undici::::::node.js::*
	cpe:2.3:a:nodejs:undici::::::node.js::*

History

16 Sep 2026, 20:41

Type	Values Removed	Values Added
CPE		cpe:2.3:a:nodejs:undici::::::node.js::*
First Time		Nodejs Nodejs undici
References	~~() https://cna.openjsf.org/security-advisories.html -~~	() https://cna.openjsf.org/security-advisories.html - Vendor Advisory
References	~~() https://github.com/nodejs/undici/security/advisories/GHSA-3wwx-pv8p-q78v -~~	() https://github.com/nodejs/undici/security/advisories/GHSA-3wwx-pv8p-q78v - Vendor Advisory

Information

Published : 2026-09-04 17:17

Updated : 2026-09-16 20:41

NVD link : CVE-2026-85024

Mitre link : CVE-2026-85024

CVE.ORG link : CVE-2026-85024

JSON object : View

Products Affected

nodejs

undici

CWE

CWE-248

Uncaught Exception

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