Uncaught Exception in undici - CVE-2026-85024
Published: September 6, 2026
Vulnerability identifier: #VU147172
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-85024
CWE-ID: CWE-248
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an uncaught exception in the WebSocket permessage-deflate decompression handler when processing a compressed WebSocket message that exceeds the decompressed-payload size limit and contains a malformed DEFLATE block. A remote attacker can send a specially crafted compressed WebSocket message to cause a denial of service.
The internal InflateRaw error listener is removed while the stream continues running, causing an unhandled Z_DATA_ERROR to terminate the Node.js process.
Affected software
undici
How to mitigate CVE-2026-85024
Install security update from vendor's website.
undici - addressed in versions 6.28.1, 7.29.1, 8.10.2