CVE-2026-67195: Perspective 5.0.0 RCE via eval() Expression Injection

Perspective 5.0.0 contains a remote code execution vulnerability that allows unauthenticated attackers to execute arbitrary operating system commands by submitting crafted expression strings to the PolarsVirtualServer backend, which passes client-supplied input directly to Python's eval() with only builtins={} cleared. Attackers can exploit Python object attribute traversal through the interpreter's loaded class list to reach subprocess.Popen via a TableValidateExprReq or TableMakeViewReq protobuf message, achieving arbitrary command execution in the Perspective host process.