{"api_version":"1","generated_at":"2026-08-25T19:43:19+00:00","cve":"CVE-2026-55637","urls":{"html":"https://cve.report/CVE-2026-55637","api":"https://cve.report/api/cve/CVE-2026-55637.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-55637","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-55637"},"summary":{"title":"genieacs-mcp: DNS rebinding reaches local GenieACS MCP Streamable HTTP transport","description":"genieacs-mcp is an MCP server for GenieACS written in Go. Prior to 0.3.2, the Streamable HTTP transport in cmd/server/main.go creates an unauthenticated /mcp listener on the default MCP_LISTEN_ADDR value 127.0.0.1:8080 when MCP_AUTH_TOKEN is unset and the httpSrv.Start(addr) branch does not validate the Host or Origin headers. A malicious website can use DNS rebinding to send browser requests with attacker-controlled Host and Origin values to the loopback listener, initialize an MCP session, list tools, and invoke operations against the GenieACS NBI configured by ACS_URL. Successful exploitation can expose or modify CPE management state, including device reboots, firmware tasks, TR-069 parameter changes, presets, provisions, tags, connection requests, and task operations. The npm wrapper is not affected because it forces TRANSPORT=stdio and does not expose an HTTP listener. This issue is fixed in version 0.3.2.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-08-25 18:17:56","updated_at":"2026-08-25 19:16:50"},"problem_types":["CWE-346","CWE-346 CWE-346: Origin Validation 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Prior to 0.3.2, the Streamable HTTP transport in cmd/server/main.go creates an unauthenticated /mcp listener on the default MCP_LISTEN_ADDR value 127.0.0.1:8080 when MCP_AUTH_TOKEN is unset and the httpSrv.Start(addr) branch does not validate the Host or Origin headers. A malicious website can use DNS rebinding to send browser requests with attacker-controlled Host and Origin values to the loopback listener, initialize an MCP session, list tools, and invoke operations against the GenieACS NBI configured by ACS_URL. Successful exploitation can expose or modify CPE management state, including device reboots, firmware tasks, TR-069 parameter changes, presets, provisions, tags, connection requests, and task operations. The npm wrapper is not affected because it forces TRANSPORT=stdio and does not expose an HTTP listener. This issue is fixed in version 0.3.2.","Type":"Description","Title":"genieacs-mcp: DNS rebinding reaches local GenieACS MCP Streamabl"}]}}}