{"id":"CVE-2026-55637","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-55637","summary":"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…","details":"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.","published":"2026-08-25T18:17:56.157","modified":"2026-08-25T18:17:56.157","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[],"fix":{"url":"https://github.com/GeiserX/genieacs-mcp/commit/577306d78190622eee97e362b042a69499ef373f","label":"GeiserX/genieacs-mcp@577306d"},"references":[{"type":"WEB","url":"https://github.com/GeiserX/genieacs-mcp/commit/577306d78190622eee97e362b042a69499ef373f"},{"type":"WEB","url":"https://github.com/GeiserX/genieacs-mcp/pull/26"},{"type":"WEB","url":"https://github.com/GeiserX/genieacs-mcp/releases/tag/v0.3.2"},{"type":"WEB","url":"https://github.com/GeiserX/genieacs-mcp/security/advisories/GHSA-cmwv-wf9p-p8wx"}],"provenance":{"sources":["OSV.dev","NVD","FIRST.org (EPSS)"],"lastVerified":"2026-08-25T18:17:56.157"}}