CVE-2026-81096
Severity CVSS v4.0:
CRITICAL
Type:
CWE-94
Code Injection
Publication date:
27/08/2026
Last modified:
27/08/2026
Description
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.
Impact
Base Score 4.0
9.30
Severity 4.0
CRITICAL
Base Score 3.x
10.00
Severity 3.x
CRITICAL
References to Advisories, Solutions, and Tools
- https://github.com/mims-harvard/ToolUniverse
- https://github.com/mims-harvard/ToolUniverse/pull/251
- https://github.com/mims-harvard/ToolUniverse/security/advisories/GHSA-pxwq-22vf-87fm
- https://www.vulncheck.com/advisories/tooluniverse-through-1.2.6-unauthenticated-remote-code-execution-via-python-code-executor-sandbox-escape