CVE-2026-54463: Faye Websocket-Driver

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.8.1, draft versions of the WebSocket protocol in websocket-driver include a length header that allows an arbitrarily large integer to be encoded as bytes with the high bit set, and a server or client can send an indefinite sequence of 0x80 or higher bytes that the peer parses into an ever-growing Ruby integer. This can make a WebSocket connection consume an unbounded amount of memory and lead to the host process running out of memory. This issue is fixed in version 0.8.1.

Affected products

• Faye Websocket-Driver: before 0.8.1 (fixed in 0.8.1)

Published 2026-07-17. Last modified 2026-08-06.