CVE-2026-35626: OpenClaw < 2026.3.22 - Unauthenticated Resource Exhaustion via Voice Call Webhook

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-09 · updated 2026-06-17
Weakness: CWE-405

Description

OpenClaw before 2026.3.22 contains an unauthenticated resource exhaustion vulnerability in voice call webhook handling that buffers request bodies before provider signature checks. Attackers can send large or malicious webhook requests to exhaust server resources without authentication by bypassing signature validation.

Affected products

OpenClaw: before 2026.3.22 — fixed in 2026.3.22

How to fix

Upgrade to a fixed version: OpenClaw 2026.3.22. Check the vendor advisory for mitigations.

References

https://github.com/openclaw/openclaw/commit/630f1479c44f78484dfa21bb407cbe6f171dac87
https://github.com/openclaw/openclaw/commit/651dc7450b68a5396a009db78ef9382633707ead
https://github.com/openclaw/openclaw/security/advisories/GHSA-rm59-992w-x2mv
https://www.vulncheck.com/advisories/openclaw-unauthenticated-resource-exhaustion-via-voice-call-webhook

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