CVE-2026-54463

Description

### 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.

How to fix CVE-2026-54463

To remediate CVE-2026-54463, upgrade the affected package to a fixed version below.

• —upgrade to 0.8.1 or later

Is CVE-2026-54463 being exploited?

No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-54463.

Affected packages (1)

• from 0, < 0.8.1

CVSS scores

References (5)

• PATCHgithub.com/faye/websocket-driver-ruby
• WEBgithub.com/faye/websocket-driver-ruby/releases/tag/0.8.1
• WEBgithub.com/faye/websocket-driver-ruby/security/advisories/GHSA-ghhp-3qvg-889p
• WEBgithub.com/rubysec/ruby-advisory-db/blob/master/gems/websocket-driver/CVE-2026-54463.yml