CVE Catalog

CVE-2026-101057

LowCVSS 3.1
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.11%

1th percentile - higher than 1% of all known CVEs

Summary

The MCP plugin utcp-mcp (part of python-utcp) through 1.1.2 connects to HTTP and WebSocket MCP server URLs from mcpServers configuration without the ensure_secure_url validation, allowing connections to non-HTTPS/WSS or internal hosts. Fixed in 1.1.3 by validating server URLs before connection.

Risk Assessment

An attacker could intercept MCP communication (e.g., credentials) or connect to internal hosts, potentially leading to data leakage or unauthorized access to internal resources.

Recommendation

Upgrade utcp-mcp to version 1.1.3 or later, which validates server URLs before connection. Additionally, ensure mcpServers configuration uses only secure HTTPS/WSS URLs.

Related vulnerabilities

Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS