CVE-2026-64651

Name of the Vulnerable Software and Affected Versions @ai-sdk/harness-opencode versions prior to 1.0.28

Description The tool connects HarnessAgent to OpenCode via a sandboxed bridge. The tool relay authorizes requests from any process whose command line contains the allowed helper script path host-tool-mcp.mjs. This allows untrusted code executing in the sandbox to invoke arbitrary host-exposed tools, such as secret lookups, deployment operations, and cloud API calls, without a model-authorized tool-call event. Exploitation requires a Linux environment, an active harness session with host-provided tools, and untrusted code executing in the sandbox, such as a malicious dependency, build script, or lifecycle hook.

Recommendations Update to version 1.0.28 or later. Do not run the OpenCode harness on untrusted repositories or with untrusted dependencies. Limit host-exposed tools to non-sensitive operations when working with untrusted code.