CVE-2026-81096
CriticalCVSS 10.0Summary
ToolUniverse ran caller-supplied Python inside an escapable sandbox on a server with no authentication. The executor left attribute-lookup builtins available and did not block dunder attributes reached via string lookup or permitted modules, allowing escape to process and subprocess modules. HTTP and MCP servers bound to all interfaces with debugging enabled and no authentication, so any caller could execute code as the server process. Version 1.3.0 adds bearer-token authentication, defaults to loopback, and hardens attribute checks.
Risk Assessment
An unauthenticated attacker can execute arbitrary code on the server, leading to full system and data compromise.
Recommendation
Update ToolUniverse to version 1.3.0 or later, which includes security fixes, and configure authentication.
Original NVD description (English source)
ToolUniverse ran caller-supplied Python inside a sandbox that could be escaped, on a server that required no authentication. The executor behind the python_code_executor tool, in python_executor_tool.py, inspected the submitted source for a denied list of attribute names and calls but left the attribute-lookup builtins available and did not stop a dunder attribute reached through a string lookup or through a module already permitted, so a caller could walk from a literal's class to its base and enumerate subclasses to obtain a reference to the process and subprocess modules. A per-call argument also let the caller widen the import allow-list before the inspection ran. The HTTP and MCP servers in http_api_server.py and smcp_server.py bound to every interface with debugging enabled and no authentication, so any caller able to reach the port executed code as the server process. Version 1.3.0 adds bearer-token authentication, defaults the bind address to loopback, and hardens the attribute checks.