OpenClaw Remote Filesystem Bridge Sandbox Escape Vulnerability (CVE-2026-41296)

OpenClaw, a software application, is susceptible to a critical security vulnerability identified as CVE-2026-41296. Specifically, versions prior to 2026.3.31 contain a time-of-check-time-of-use (TOCTOU) race condition within the readFile function of its remote filesystem bridge. This flaw allows malicious actors to potentially escape the intended sandbox environment. The vulnerability arises from the separation of path validation and file read operations, creating a window of opportunity for attackers to manipulate file access and circumvent security controls. Successful exploitation could lead to unauthorized access to sensitive files and data residing outside the designated sandbox. Defenders should prioritize patching to version 2026.3.31 or later to mitigate this risk.

Attack Chain

1. The attacker gains initial access to a system running a vulnerable version of OpenClaw.
2. The attacker crafts a request targeting the readFile function in the remote filesystem bridge.
3. The request includes a path to a file intended to be accessed within the sandbox.
4. OpenClaw performs a path validation check on the requested file path, which initially passes.
5. Between the path validation check and the actual file read operation, the attacker manipulates the filesystem, potentially through a symbolic link or other means, to point the original path to a file outside the sandbox.
6. The readFile function proceeds to read the file located at the modified path, bypassing the intended sandbox restrictions.
7. The contents of the arbitrary file are then exposed to the attacker.
8. The attacker obtains sensitive information or achieves further escalation of privileges based on the exposed file contents.

Impact

Successful exploitation of CVE-2026-41296 can lead to a complete bypass of the OpenClaw sandbox environment. This allows attackers to read arbitrary files on the system, potentially exposing sensitive data such as configuration files, credentials, or user data. The impact could range from information disclosure to privilege escalation, depending on the nature of the files accessed. While the specific number of affected installations is unknown, any system running a vulnerable version of OpenClaw is at risk.

Recommendation

• Upgrade OpenClaw to version 2026.3.31 or later to patch CVE-2026-41296.
• Implement the process creation rule below to detect potential exploitation attempts that involve spawning unusual processes after OpenClaw accesses files (Sigma rule: "Detect OpenClaw Sandbox Escape - Process Creation").
• Deploy the file access monitoring rule to detect OpenClaw accessing sensitive files outside of its intended sandbox (Sigma rule: "Detect OpenClaw Unusual File Access").