CVE-2026-41405
Published: 28 April 2026
Summary
CVE-2026-41405 is a high-severity Incorrect Behavior Order: Early Amplification (CWE-408) vulnerability in Openclaw Openclaw. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 36.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 AC-14 (Permitted Actions Without Identification or Authentication) and SC-5 (Denial-of-service Protection).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Limits permitted actions without identification or authentication to prevent resource-intensive parsing of MS Teams webhook payloads prior to JWT validation.
Implements denial-of-service protections to limit effects of resource exhaustion from unauthenticated malicious webhook payloads.
Provides timely flaw remediation by upgrading to OpenClaw 2026.3.31, which reorders JWT validation before payload parsing.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Vulnerability in public-facing OpenClaw webhook handler allows unauthenticated remote exploitation via crafted payloads to cause application-level resource exhaustion and DoS.
NVD Description
OpenClaw before 2026.3.31 parses MS Teams webhook request bodies before performing JWT validation, allowing unauthenticated attackers to trigger resource exhaustion. Remote attackers can send malicious Teams webhook payloads to exhaust server resources by bypassing authentication checks.
Deeper analysisAI
CVE-2026-41405 is a resource exhaustion vulnerability in OpenClaw versions prior to 2026.3.31. The issue stems from the software parsing Microsoft Teams webhook request bodies before performing JWT validation, which allows attackers to trigger excessive resource consumption without authentication. This flaw, classified under CWE-408 (Incorrect Behavior Order: Early Validation), carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), highlighting its high-impact availability disruption potential over the network with low complexity.
Unauthenticated remote attackers can exploit this vulnerability by sending specially crafted malicious MS Teams webhook payloads to affected OpenClaw servers. By bypassing the authentication checks through premature parsing, attackers can cause the server to exhaust CPU or memory resources, leading to denial-of-service conditions that disrupt service availability for legitimate users.
Mitigation is addressed in OpenClaw version 2026.3.31 and later, as detailed in the project's GitHub security advisory (GHSA-p464-m8x6-vhv8) and the associated patch commit (3834d47099dd13c8244ed6de8b9ea9855c553623), which reorder validation to parse payloads only after JWT checks. Administrators should upgrade to the fixed version promptly, as noted in the VulnCheck advisory, and consider network-level filtering of unexpected webhook traffic in the interim.
Details
- CWE(s)