CVE-2026-54463: websocket-driver: Memory exhaustion via abuse of protocol length headers
Impact
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 server or client can make the other peer parse these bytes into an ever-growing integer. Since Ruby integers are arbitrary precision, this can be used to make a WebSocket connection consume an unbounded amount of memory and lead to the host process running out of memory.
Patches
The issue has been patched in version 0.8.1. All users should upgrade to this version.
Workarounds
No known workarounds exist.
Acknowledgements
This issue was discovered and reported by Pranjali Thakur, DepthFirst Security Research Team.
Other sources
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.
— MITRE
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-54463?
The severity of CVE-2026-54463 is medium with a CVSS score of 6.9.
What is the impact of CVE-2026-54463?
CVE-2026-54463 can lead to memory exhaustion due to abuse of protocol length headers in the WebSocket protocol.
How do I fix CVE-2026-54463?
To fix CVE-2026-54463, update the websocket-driver gem to version 0.8.1 or later.
Which software is affected by CVE-2026-54463?
The websocket-driver gem used in Ruby applications is affected by CVE-2026-54463.
When was CVE-2026-54463 published?
CVE-2026-54463 was published on July 15, 2026.