Resource exhaustion in Faye Websocket-Driver

CVE-2026-54463

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.

EPSS: 0.003 (27.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-54463?
CVE-2026-54463 is a high-severity vulnerability in Faye Websocket-Driver, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-07-17.
How severe is CVE-2026-54463?
High severity. CVSS v3 base score is 7.5 out of 10.