Executive brief
OpenClaw is a local AI assistant that decodes base64-encoded data as part of its functionality. Multiple code paths fail to enforce size limits before allocating memory, allowing a malicious input to trigger excessive memory allocation and cause the application to become unresponsive or crash.
Technical details
The vulnerability exists in OpenClaw's base64 decoding implementation where multiple code paths allocate memory before validating the decoded output size limit. This is a classic improper resource validation flaw (CWE-770) that allows an attacker to craft malicious base64-encoded input that, when decoded, exceeds the intended size limits. The vulnerability requires authenticated access (PR:L) and network reachability. An attacker can exploit this to cause a denial of service by exhausting available memory, forcing the application to crash or become unresponsive. The fix was released in version 2026.4.8 and verified against regression tests.
Affected products
- OpenClaw OpenClaw <=v2026.4.2
Timeline
- 2026-04-09: disclosed
- 2026-04-08: patched: Patched version 2026.4.8 released