CVE-2026-54466: Faye Websocket-Driver

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.7.5, the frame format in draft versions of the WebSocket protocol includes a length header that allows an arbitrarily large integer to be encoded as a sequence of bytes with the high bit set. By sending an indefinite sequence of bytes with values 0x80 or above, a client can make the server parse these bytes into an ever-growing integer in lib/websocket/driver/draft75.js; because JavaScript numbers are 64-bit floating point values, this number will eventually lose precision and lead to the subsequent payload being parsed incorrectly. This issue is fixed in version 0.7.5.

Affected products

• Faye Websocket-Driver: before 0.7.5 (fixed in 0.7.5)

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