Summary
websocket-driver: Memory exhaustion via abuse of protocol length headers
Workarounds
No known workarounds exist.
Acknowledgements
This issue was discovered and reported by Pranjali Thakur, DepthFirst Security Research Team.
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.
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
The issue has been patched in version 0.8.1. All users should upgrade to this version.
Frequently Asked Questions
- What is CVE-2026-54463? CVE-2026-54463 is a medium-severity uncontrolled resource consumption vulnerability in websocket-driver (rubygems), affecting versions < 0.8.1. It is fixed in 0.8.1. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- Which versions of websocket-driver are affected by CVE-2026-54463? websocket-driver (rubygems) versions < 0.8.1 is affected.
- Is there a fix for CVE-2026-54463? Yes. CVE-2026-54463 is fixed in 0.8.1. Upgrade to this version or later.
- Is CVE-2026-54463 exploitable, and should I be worried? Whether CVE-2026-54463 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-54463 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-54463? Upgrade
websocket-driverto 0.8.1 or later.