OpenClaw before 2026.3.25 parses JSON request bodies before validating webhook signatures, allowing unauthenticated attackers to force resource-intensive parsing operations.
Date: 2026-04
Affected: openclaw/openclaw
Attack vector: dos
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-35640
CWE: CWE-696
CVSS: 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)

OpenClaw before 2026.3.25 parses JSON request bodies before validating webhook signatures, allowing unauthenticated attackers to force resource-intensive parsing operations. Remote attackers can send malicious webhook requests to trigger denial of service by exhausting server resources through forced JSON parsing before signature rejection.


Mitigations:

Architectural layers (MAESTRO):