CVE-2026-41399: OpenClaw < 2026.3.28 - Denial of Service via Unbounded Pre-auth WebSocket Upgrades

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: 2026-04-28 · updated 2026-06-17
Weakness: CWE-770

Description

OpenClaw before 2026.3.28 accepts unbounded concurrent unauthenticated WebSocket upgrades without pre-authentication budget allocation. Unauthenticated network attackers can exhaust socket and worker capacity to disrupt WebSocket availability for legitimate clients.

Affected products

OpenClaw: before 2026.3.28 — fixed in 2026.3.28

How to fix

Upgrade to a fixed version: OpenClaw 2026.3.28. Check the vendor advisory for mitigations.

References

https://github.com/openclaw/openclaw/security/advisories/GHSA-f44p-c7w9-7xr7
https://www.vulncheck.com/advisories/openclaw-denial-of-service-via-unbounded-pre-auth-websocket-upgrades

Get alerted when CVE-2026-41399 or the next vulnerability affects your stack