CVE-2026-54466: websocket-driver: Message corruption via abuse of protocol length headers

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-17 · updated 2026-10-24
Weakness: CWE-130

Description

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-ruby: before 0.7.5 — fixed in 0.7.5
Npm Websocket-Driver: before 0.7.5 — fixed in 0.7.5

How to fix

Upgrade to a fixed version: faye websocket-driver-ruby 0.7.5; Npm Websocket-Driver 0.7.5. Check the vendor advisory for mitigations.

References

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