CVE-2026-53819: OpenClaw < 2026.5.27 - Arbitrary Homebrew Executable Execution via Workspace .env Override

Synopsis

An arbitrary code execution vulnerability affects OpenClaw before version 2026.5.27. The flaw is reachable over the network and requires no authentication, but a victim must take an action during skill installation for the attack to succeed; specifically, a workspace .env file can be crafted to override the Homebrew executable selection, causing an unintended executable to run during skill setup. Successful exploitation gives an attacker full read, write, and availability impact on the host running OpenClaw. A patched-image rebuild at version 2026.5.27 is available on HarborGuard for affected environments.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The attacker must be able to reach the target service over the network to deliver a malicious workspace .env file to the victim.

• AuthenticationNot required

  No credentials or account are needed; the attack can be initiated by an unauthenticated remote party.

• Victim interactionRequired

  A user on the target system must trigger the skill install flow, such as opening or processing the malicious workspace, for the override to take effect.

• Attack complexityDetail

  Exploitation is reliable and condition-free once the victim interacts; no race conditions or special environmental factors are required.

Blast Radius

• A successful attacker executes arbitrary Homebrew-compatible binaries under the context of the user running OpenClaw, gaining full control over that process.
• All data readable by the OpenClaw process is exposed, including environment variables, secrets loaded from .env files, and any files accessible to that user.
• An attacker can write or modify files on the host, including replacing binaries, altering configuration, or planting persistence mechanisms.
• The OpenClaw process and any services it manages can be crashed or destabilized, disrupting skill setup workflows and dependent operations.