What’s Vulnerable › Vulnerabilities

CVE-2026-100558: OpenClaw before 2026.8.1 Resource Exhaustion via WebSocket Upgrade

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-26 · updated 2026-09-28
• Weakness: CWE-400

Description

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.

Affected products

• OpenClaw: before 2026.8.1 — fixed in 2026.8.1

How to fix

Upgrade to a fixed version: OpenClaw 2026.8.1. Check the vendor advisory for mitigations.

References

• https://github.com/openclaw/openclaw/security/advisories/GHSA-4r25-35qc-fr6j
• https://www.vulncheck.com/advisories/openclaw-before-2026.8.1-resource-exhaustion-via-websocket-upgrade

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