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.

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History

Fri, 28 Aug 2026 16:45:00 +0000

Type Values Removed Values Added
First Time appeared Mims-harvard
Mims-harvard tooluniverse
Vendors & Products Mims-harvard
Mims-harvard tooluniverse

Thu, 27 Aug 2026 18:00:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 27 Aug 2026 16:45:00 +0000

Type Values Removed Values Added
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.
Title ToolUniverse through 1.2.6 Unauthenticated Remote Code Execution via python_code_executor Sandbox Escape
Weaknesses CWE-94
References
Metrics cvssV3_1

{'score': 10, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'}

cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-27T18:13:19.374Z

Reserved: 2026-08-26T16:00:32.344Z

Link: CVE-2026-81096

cve-icon Vulnrichment

Updated: 2026-08-27T18:13:11.012Z

cve-icon NVD

Status : Received

Published: 2026-08-27T17:20:51.950

Modified: 2026-08-27T20:18:49.567

Link: CVE-2026-81096

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-28T16:14:32Z

Weaknesses