CVE-2026-100558

OpenClaw versions before 2026.8.1 contain a resource exhaustion vulnerability in the Gateway listener that allows unauthenticated clients to retain response sockets by sending WebSocket upgrade requests without matching connection semantics. Attackers can repeatedly send malformed upgrade requests to exhaust listener resources and cause denial of service without consuming the WebSocket pre-auth connection budget.

  • Published Sep 26, 2026
  • CVSS 8.7 high
  • 0.3% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-100558 at the National Vulnerability Database