utcp-mcp before 1.1.3 SSRF via unvalidated MCP server URL (CVE-2026-101057) | HOL Guard CVE

Low · CVSS 2.3CVE-2026-101057

utcp-mcp before 1.1.3 SSRF via unvalidated MCP server URL

Answer in brief

CVE-2026-101057 records a Low severity (CVSS 2.3) vulnerability in utcp-mcp before 1.1.3 SSRF via unvalidated MCP server URL. The current sources do not mark it as known exploited. The current feed maps universal-tool-calling-protocol/python-utcp (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 27, 2026Updated Sep 27, 2026Source checked Sep 27, 2026First seen by HOL Sep 27, 2026Material review Sep 27, 2026

Upstream Advisory

Key facts

Risk: Low · CVSS 2.3
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 2.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps universal-tool-calling-protocol/python-utcp (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
universal-tool-calling-protocol/python-utcpgeneric	>=0 <1.1.3	1.1.3

Recommended response

Check inventory. Check lockfiles and deployed manifests for universal-tool-calling-protocol/python-utcp.
Review the reported fix. Update universal-tool-calling-protocol/python-utcp to 1.1.3 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 27, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 27, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.