CVE-2026-54463

mediumcovered by 2 sourcesfirst seen 2026-07-15

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.

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Exploitation outlook

Low exploitation risk0.32% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 25% of all EPSS-scored CVEs.

Advisory coverage (2)

unknownCVE-2026-54463: websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.8.1, draft ver…nvd · 2026-07-17
mediumGHSA-ghhp-3qvg-889p: websocket-driver: Memory exhaustion via abuse of protocol length headersghsa · 2026-07-15

External references

NVD record for CVE-2026-54463

CVE.org record

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