universal-tool-calling-protocol python-utcp up to 1.1.1 cli_communication_protocol.py _substitute_utcp_args os command injection

Summaryinfo

A vulnerability has been found in universal-tool-calling-protocol python-utcp up to 1.1.1 and classified as critical. This affects the function _substitute_utcp_args of the file cli_communication_protocol.py. This manipulation causes os command injection. This vulnerability appears as CVE-2026-45369. The attack may be initiated remotely. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in universal-tool-calling-protocol python-utcp up to 1.1.1. It has been declared as critical. Affected by this vulnerability is the function _substitute_utcp_args of the file cli_communication_protocol.py. The manipulation with an unknown input leads to a os command injection vulnerability. The CWE definition for the vulnerability is CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

python-utcp is the python implementation of UTCP. Prior to 1.1.3, the _substitute_utcp_args method in cli_communication_protocol.py inserts user-controlled tool_args values directly into shell command strings without any sanitization or escaping. These commands are then executed via /bin/bash -c (Unix) or powershell.exe -Command (Windows), allowing an attacker to inject arbitrary shell commands. This vulnerability is fixed in 1.1.3.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-45369 since 05/12/2026. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1202 according to MITRE ATT&CK.

Upgrading to version 1.1.2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-30475). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Programming Language Software

Vendor

• universal-tool-calling-protocol

Name

• python-utcp

Version

• 1.1.0
• 1.1.1

Website

• Product: https://github.com/universal-tool-calling-protocol/python-utcp/

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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