Resource exhaustion in Openclaw
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.
Vulnerability class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.003 (20.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 20.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-4r25-35qc-fr6j) (vendor-advisory)
- VulnCheck Advisory: OpenClaw before 2026.8.1 Resource Exhaustion via WebSocket Upgrade (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100558?
- CVE-2026-100558 is a high-severity vulnerability in Openclaw, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-09-26.
- How severe is CVE-2026-100558?
- High severity. CVSS v3 base score is 7.5 out of 10.