CVE-2026-53864: OpenClaw < 2026.5.26 - Insufficient Environment Variable Sanitization in Node.js Control Variables

Synopsis

Insufficient environment variable sanitization in OpenClaw before version 2026.5.26 allows attackers who can write to workspace .env files, tool environment overrides, or skill environment blocks to inject malicious Node.js control variables. The vulnerability is reached over the network by a low-privileged authenticated user, with no victim interaction required. Successful exploitation gives the attacker full read and write access to data handled by affected child processes, though service availability is not directly impacted. A patched-image rebuild at version 2026.5.26 is available on HarborGuard for environments running an affected version.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The vulnerable endpoint is exposed over the network, meaning an attacker must be able to reach the service remotely to deliver malicious environment variable input.

• AuthenticationRequired

  A low-privilege account is sufficient; the attacker needs valid credentials to access workspace .env files, tool environment overrides, or skill environment blocks.

• Victim interactionNot required

  No victim action is needed; the attacker can inject malicious Node.js control variables without any user interaction on the target side.

• Attack complexityDetail

  Base exploit logic is condition-free, but the attack requires a specific prerequisite condition (AT:P) such as write access to an environment configuration surface, making opportunistic exploitation less reliable.

Blast Radius

• Reads environment variable state and any secrets or tokens accessible to child processes spawned by OpenClaw.
• Writes to or redirects coverage output paths, allowing an attacker to manipulate build artifacts or overwrite files reachable by the Node.js process.
• Injects Node.js control variables that influence child process behavior, enabling the attacker to alter execution flow in downstream tooling.
• Impact is contained to the confidentiality and integrity of the affected process and its data; the service itself does not crash and availability is unaffected.