MCP Fetch ignores well-known NAT64 embedded private IPv4

Evidence record

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Claim-level citations (2)

• supportsMCP Fetch egress policy missed IPv4 addresses embedded in NAT64: The advisory demonstrates a classification bypass for the well-known 64:ff9b::/96 prefix carrying a private/link-local IPv4 address, with routing as a stated precondition.

  NAT64 address classification; routing precondition; remediation

• supportsMCP Fetch egress policy missed IPv4 addresses embedded in NAT64: GHSA-66qx-2266-pmj6 demonstrates that an embedded link-local IPv4 address in 64:ff9b::/96 passed the MCP Fetch public-address classifier, but it makes NAT64 routing a prerequisite for reaching the IPv4 target.

  Summary; 64:ff9b::/96 classifier reproduction and DNS64/NAT64 routing prerequisite