What happened
CVE-2026-61546 (CVSS 8.8): AnkiMCP, an Anki addon implementing an MCP server, prior to 0.21.0 globally disables FastMCP DNS-rebinding protection via TransportSecuritySettings with enable_dns_rebinding... set in mcp_server.py, so the server accepts connections that the DNS-rebinding protection would otherwise block.
Why it matters
An MCP server intended to run on the user's local Anki install becomes reachable by a malicious web page that rebinds DNS to the localhost server, letting remote content drive the AI-assistant-to-Anki tool surface (creating/modifying flashcard data) without a trusted origin check.
Attack vector
A malicious webpage performs a DNS-rebinding attack to reach the localhost MCP server (DNS-rebinding protection disabled), issuing MCP tool calls against the Anki application.
Affected systems
AnkiMCP (anki-mcp-server-addon) before 0.21.0.
Mitigation
Upgrade AnkiMCP to 0.21.0 or later (commit 6dcb6939b0ecc0801f45cf0d241dc946aad1654f).