CVE-2026-53831: OpenClaw's POSIX node system.run safe-bin allowlist could be widened by shell expansion

Summary

On POSIX nodes, OpenClaw's system.run safe-bin checks could approve a command before shell expansion changed how the command was interpreted. A value that appeared to be a safe-bin argument could expand into additional shell words and become a file operand.

This issue is limited to paired POSIX node execution through system.run with safe-bin or allowlist-style auto-approval. It is not an unauthenticated node takeover.

Affected configurations

This affects deployments where:

• a POSIX node is paired to the gateway
• system.run is reachable by an authenticated operator or agent flow
• exec policy uses safe-bin or allowlist-based auto-approval
• the approved command contains shell-expanded values that can change argv shape

Impact

A lower-privilege operator flow could cause an approved safe-bin command to read a node-local file that was not intended by the policy. Depending on the local files available to the node process, this could expose OpenClaw configuration data or other node-local information.

The issue is a policy-enforcement gap in argv validation, not a general statement that every safe-bin command is unsafe.

Patched Versions

The first stable patched version is 2026.5.18.

Mitigations

Upgrade to [email protected] or later. Before upgrading, avoid broad safe-bin auto-approval for commands that can read arbitrary paths, and prefer explicit approval for node commands that touch local files.