CVE-2026-28478
Published: 05 March 2026
Summary
CVE-2026-28478 is a high-severity Allocation of Resources Without Limits or Throttling (CWE-770) vulnerability in Openclaw Openclaw. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application Exhaustion Flood (T1499.003); ranked at the 34.8th 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 SC-5 (Denial-of-service Protection) and SC-6 (Resource Availability).
Deeper analysis
CVE-2026-28478 is a denial-of-service vulnerability affecting OpenClaw versions prior to 2026.2.13, published on 2026-03-05. The issue resides in the webhook handlers, which buffer request bodies without strict byte or time limits, enabling memory exhaustion. It is rated 7.5 on the CVSS v3.1 scale (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) and maps to CWE-770 (Allocation of Resources Without Limits or Throttling).
Remote unauthenticated attackers can exploit this vulnerability by sending oversized JSON payloads or slow uploads to webhook endpoints. Successful exploitation leads to memory pressure and degradation of service availability, potentially causing the application to crash or become unresponsive.
Advisories and the associated patch recommend upgrading to OpenClaw version 2026.2.13 or later, where the fix is implemented via commit 3cbcba10cf30c2ffb898f0d8c7dfb929f15f8930. Additional details are available in the GitHub security advisory GHSA-q447-rj3r-2cgh and VulnCheck's analysis at vulncheck.com.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-9924
Vulnerability details
OpenClaw versions prior to 2026.2.13 contain a denial of service vulnerability in webhook handlers that buffer request bodies without strict byte or time limits. Remote unauthenticated attackers can send oversized JSON payloads or slow uploads to webhook endpoints causing memory…
more
pressure and availability degradation.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Vulnerability enables remote unauthenticated memory exhaustion via oversized/slow webhook payloads, directly mapping to Application Exhaustion Flood (T1499.003).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
SC-5 directly protects against denial-of-service events such as memory exhaustion from oversized JSON payloads or slow uploads to webhook endpoints.
SC-6 enforces resource allocation policies and usage monitoring to prevent unlimited buffering of request bodies causing availability degradation.
SI-9 restricts the amount and length of information inputs, mitigating oversized payloads and slow uploads without byte or time limits in webhook handlers.