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

High 8.7 Published Updated

Unauthenticated attackers can exhaust resources via unbounded WebSocket upgrades, causing denial of service for legitimate clients.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
Available

What is CVE-2026-41399?

CVE-2026-41399 is a high-severity denial of service vulnerability in Openclaw Openclaw, published on 28 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-770

Which versions are affected by CVE-2026-41399?

2 open source packages ship an affected version, including openclaw. It affects 1 product.

PackageAffectedFixed in
openclaw npmAll versions2026.3.28
openclaw npmAll versions2026.3.28

Products include Openclaw Openclaw.

How do I fix CVE-2026-41399?

Upgrade openclaw to 2026.3.28 or later.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2026-41399 being exploited?

There is no known exploitation of CVE-2026-41399 in the wild and no public exploit code.

All Openclaw Openclaw vulnerabilities

Sources

Also known as GHSA-f44p-c7w9-7xr7, MINI-f43m-8fcx-q99f.

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