HKUDS nanobot up to 0.2.1 MCP enabledTools Scope mcp.py connect_mcp_servers access control

Summaryinfo

A vulnerability labeled as critical has been found in HKUDS nanobot up to 0.2.1. The impacted element is the function connect_mcp_servers of the file nanobot/agent/tools/mcp.py of the component MCP enabledTools Scope Handler. Executing a manipulation can lead to access control. This vulnerability appears as CVE-2026-19244. The attack may be performed from remote. In addition, an exploit is available. The affected component should be upgraded. Multiple issues were reported to the project. They reacted with a high level of professionalism and kindness: "Both reports describe the same root cause: MCP resource and prompt wrappers could be registered outside the intended enabledTools scope. The registration boundary was corrected".

Detailsinfo

A vulnerability was found in HKUDS nanobot up to 0.2.1. It has been declared as critical. This vulnerability affects the function connect_mcp_servers of the file nanobot/agent/tools/mcp.py of the component MCP enabledTools Scope Handler. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect confidentiality, integrity, and availability.

The advisory is available at github.com. This vulnerability was named CVE-2026-19244. The exploitation appears to be easy. The attack can be initiated remotely. Additional levels of successful authentication are necessary for exploitation. Technical details and also a public exploit are known. This vulnerability is assigned to T1068 by the MITRE ATT&CK project.

It is possible to download the exploit at gist.github.com. It is declared as proof-of-concept. Multiple issues were reported to the project. They reacted with a high level of professionalism and kindness: "Both reports describe the same root cause: MCP resource and prompt wrappers could be registered outside the intended enabledTools scope. The registration boundary was corrected".

Upgrading to version 0.3.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 4436 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Vendor

• HKUDS

Name

• nanobot

Version

• 0.2.0
• 0.2.1

Website

• Product: https://github.com/HKUDS/nanobot/

CPE 2.3info

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CPE 2.2info

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Submitinfo

Accepted

• Submit #865116: HKUDS nanobot 0.2.1 Improper Access Control in MCP Capability Registration (CWE-284) (by Eric-c)

Duplicate

• Submit #XXXXXX: Xxxxx Xxxxxxx X.x.x Xxxxxxxx Xxxxxx Xxxxxxx Xx Xxx Xxxxxxx Xxxxxxxx (xxx-xxx) (by Eric-c)

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