CVE-2026-29609
Published: 05 March 2026
Summary
CVE-2026-29609 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 34.0th 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-2026-29609 is a denial-of-service vulnerability in OpenClaw versions prior to 2026.2.14. The flaw exists in the fetchWithGuard function, which allocates entire response payloads into memory before applying maxBytes limits. This leads to potential memory exhaustion when handling oversized responses, corresponding to CWE-770 (Allocation of Resources Without Limits or Throttling) and carrying 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).
Remote, unauthenticated attackers can exploit the vulnerability over the network with low complexity by serving oversized HTTP responses that lack content-length headers. Successful exploitation triggers unbounded memory allocation in the affected component, resulting in resource exhaustion and loss of availability for the OpenClaw application.
The GitHub Security Advisory (GHSA-j27p-hq53-9wgc) and associated patch commit (00a08908892d1743d1fc52e5cbd9499dd5da2fe0) address the issue in OpenClaw 2026.2.14. The VulnCheck advisory confirms that upgrading to this version or later enforces the maxBytes limit prior to full payload allocation, mitigating the denial-of-service risk.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-9933
Vulnerability details
OpenClaw versions prior to 2026.2.14 contain a denial of service vulnerability in the fetchWithGuard function that allocates entire response payloads in memory before enforcing maxBytes limits. Remote attackers can trigger memory exhaustion by serving oversized responses without content-length headers to…
more
cause availability loss.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability directly enables an Application Exhaustion Flood (T1499.003) by allowing remote attackers to trigger unbounded memory allocation through oversized HTTP responses lacking Content-Length headers, resulting in resource exhaustion and denial of service.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly protects against denial-of-service attacks like memory exhaustion from oversized HTTP responses lacking content-length headers.
Ensures resource availability by implementing controls to prevent unbounded memory allocation from malicious oversized payloads.
Requires validation of information inputs, such as enforcing maxBytes limits before full payload allocation in fetch functions.