CVE-2026-35665
Published: 10 April 2026
Summary
CVE-2026-35665 is a medium-severity Amplification (CWE-405) vulnerability in Openclaw Openclaw. Its CVSS base score is 6.9 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Service Exhaustion Flood (T1499.002); ranked at the 29.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-21476
Vulnerability details
OpenClaw before 2026.3.24 contains an incomplete fix for CVE-2026-32011 where the Feishu webhook handler accepts request bodies with permissive limits of 1MB and 30-second timeout before signature verification. An unauthenticated attacker can exhaust server connection resources by sending concurrent slow…
more
HTTP POST requests to the Feishu webhook endpoint, blocking legitimate webhook deliveries.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Vulnerability enables direct service exhaustion via slow HTTP POST flood against webhook endpoint before auth checks.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Reduces impact of amplification attacks that overwhelm the primary site by allowing operations to shift to an equivalent alternate site.
Alternate services reduce the impact of amplification attacks that exhaust primary telecommunications resources.
Amplification attacks that exhaust the primary path are mitigated by the existence of an independent alternate path for command traffic.
Employs controls that mitigate amplification attacks causing asymmetric resource use.
Limits amplification effects by controlling how resources are allocated under high-volume or recursive load.