CVE-2026-101057

Published: Set 27, 2026 Last Modified: Set 27, 2026
ExploitDB:
Other exploit source:
Google Dorks:
LOW 2,3
Source: [email protected]
Attack Vector: network
Attack Complexity: high
Privileges Required: none
User Interaction: passive
Confidentiality: N/A
Integrity: N/A
Availability: N/A
LOW 3,1
Source: [email protected]
Attack Vector: network
Attack Complexity: high
Privileges Required: none
User Interaction: required
Scope: unchanged
Confidentiality: low
Integrity: none
Availability: none

Description

AI Translation Available

utcp-mcp (the MCP plugin of python-utcp) through 1.1.2 connects to the HTTP and WebSocket MCP server URLs given in a call template's mcpServers configuration without the ensure_secure_url validation that the HTTP-family plugins apply, so the HTTPS/WSS-or-loopback rule is not enforced. A call template naming a plain-HTTP, non-loopback MCP server URL is dialed as configured, exposing the MCP handshake to network interception and permitting cleartext connections to internal hosts. The mcpServers configuration is operator-authored rather than remote data, and the connection is an MCP handshake rather than an arbitrary request returning a body, which limits practical exploitation; the OAuth2 token_url credential path described in the original report was not reachable in the affected versions, because the OAuth2 handler was never invoked and the call template's auth field was not read. Fixed in utcp-mcp 1.1.3, which validates server URLs before any connection is made.

319

Cleartext Transmission of Sensitive Information

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Confidentiality
Potential Impacts:
Read Application Data Modify Files Or Directories Other
Applicable Platforms
Technologies: Not Technology-Specific, Cloud Computing, Mobile, ICS/OT, System on Chip, Test/Debug Hardware
Likelihood of Exploit: High
View CWE Details
https://github.com/universal-tool-calling-protocol/python-u…
https://github.com/universal-tool-calling-protocol/python-utcp/security/advisor…
https://www.vulncheck.com/advisories/utcp-mcp-before-1.1.3-…
https://www.vulncheck.com/advisories/utcp-mcp-before-1.1.3-ssrf-via-unvalidated…