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utcp-mcp before 1.1.3 SSRF via unvalidated MCP server URL

Type: advisorySource: Official CVE List1 source record

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.

Announced Source revision 1
Original source ↗

CVE-2026-101057

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-101057

python-utcp

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "vendor": "universal-tool-calling-protocol",
    "product": "python-utcp",
    "versions": [
      {
        "status": "affected",
        "version": "0",
        "lessThan": "1.1.3",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "1.1.3",
        "versionType": "semver"
      }
    ],
    "packageURL": "pkg:pypi/utcp-mcp",
    "defaultStatus": "unaffected"
  }
]
Related CVEs
CVE-2026-101057

Source reference: /cveMetadata/cveId

Publisher severity

low

Source reference: /containers/cna/metrics

Event
#4582 · Revision 1
Added to Heist Feed
Publisher date
Read the original announcement