CVE-2026-54465: websocket-driver: Memory exhaustion in HTTP header parser

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% 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-770

Description

websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.8.1, when websocket-driver is used to implement a WebSocket server on top of a TCP server using WebSocket::Driver.server() or to complement a WebSocket client, a peer can make a single connection consume an unbounded amount of memory by sending an HTTP request or response with a never-ending list of headers. This can lead to the receiving process running out of memory. This issue is fixed in version 0.8.1.

Affected products

faye websocket-driver-ruby: before 0.8.1 — fixed in 0.8.1
Rubygems Websocket-Driver: before 0.8.1; 0.1.0, 0.2.0, 0.2.1, 0.2.2, 0.2.3, 0.3.0 (+26) — fixed in 0.8.1

How to fix

Upgrade to a fixed version: faye websocket-driver-ruby 0.8.1; Rubygems Websocket-Driver 0.8.1. Check the vendor advisory for mitigations.

References

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