Network-AI is a TypeScript/Node.js multi-agent orchestrator. Prior to version 5.12.2, `AgentRuntime` promises scoped file access under a configured sandbox `basePath`, but its path containment checks use raw string prefix tests. A sandbox base such as `/tmp/network-ai-sandbox` also matches a sibling path such as `/tmp/network-ai-sandbox_evil/secret.txt`. An agent/user that can call `AgentRuntime.readFile()` or `AgentRuntime.listDir()` can read or list files outside the intended sandbox when the target path is in a sibling directory sharing the base path prefix. This breaks the documented sandbox boundary. The issue is fixed in v5.12.2. `SandboxPolicy.resolvePath()` and `isPathAllowed()` now use separator-anchored prefix checks (`resolved === base || resolved.startsWith(base + path.sep)`) for both the allow-list and block-list. A sibling directory that merely shares a name prefix (e.g. `/srv/app-evil` vs base `/srv/app`) is no longer treated as in-scope.