OpenClaw Unbounded Memory Allocation Vulnerability

The openclaw npm package, specifically versions prior to 2026.3.22, contains a vulnerability that can lead to unbounded memory allocation. This flaw occurs when the application processes HTTP error responses from remote media servers. Due to the absence of a hard size cap, the application attempts to read the entire error body into memory without limitation. An attacker could exploit this by sending a large error response, causing the openclaw application to allocate excessive memory, potentially leading to a denial-of-service condition. The fix, implemented in version 2026.3.22 and later, introduces bounded prefix reads and capped reads to prevent excessive memory usage. This vulnerability was reported by @YLChen-007.

Attack Chain

1. An attacker identifies an openclaw application using a vulnerable version (< 2026.3.22).
2. The attacker crafts a malicious HTTP response with an extremely large error body.
3. The attacker triggers the application to request a media resource from a server they control, causing the malicious HTTP response to be sent to the application.
4. The openclaw application, lacking a size cap, attempts to read the entire error body into memory using the fetch.ts component.
5. Due to the large size of the error body, the application allocates a significant amount of memory.
6. The unbounded memory allocation continues until system resources are exhausted or a failure occurs.
7. The application crashes or becomes unresponsive due to memory exhaustion.
8. The denial-of-service condition impacts the availability of the openclaw application.

Impact

Successful exploitation of this vulnerability can result in a denial-of-service (DoS) condition. An attacker can cause the openclaw application to crash or become unresponsive by exhausting available memory. This could impact any service or application relying on the vulnerable openclaw package, potentially disrupting operations and affecting user experience. The number of victims depends on the adoption rate of the vulnerable openclaw versions.

Recommendation

• Upgrade the openclaw npm package to version 2026.3.22 or later to incorporate the fix for the unbounded memory allocation vulnerability.
• Monitor network traffic for unusually large HTTP error responses originating from media servers interacting with openclaw applications (see network_connection rule below).
• Implement resource limits and monitoring on systems running openclaw to detect and mitigate excessive memory allocation.
• Deploy the provided Sigma rules to detect potential exploitation attempts in your environment (see Sigma rules below).