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.