{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-55637","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-06-16T23:52:12.057Z","datePublished":"2026-08-25T18:03:34.701Z","dateUpdated":"2026-08-25T18:24:42.746Z"},"containers":{"cna":{"title":"genieacs-mcp: DNS rebinding reaches local GenieACS MCP Streamable HTTP transport","problemTypes":[{"descriptions":[{"cweId":"CWE-346","lang":"en","description":"CWE-346: Origin Validation Error","type":"CWE"}]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"PASSIVE","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","subAvailabilityImpact":"NONE","baseScore":8.8,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N","version":"4.0"}}],"references":[{"name":"https://github.com/GeiserX/genieacs-mcp/security/advisories/GHSA-cmwv-wf9p-p8wx","tags":["x_refsource_CONFIRM"],"url":"https://github.com/GeiserX/genieacs-mcp/security/advisories/GHSA-cmwv-wf9p-p8wx"},{"name":"https://github.com/GeiserX/genieacs-mcp/pull/26","tags":["x_refsource_MISC"],"url":"https://github.com/GeiserX/genieacs-mcp/pull/26"},{"name":"https://github.com/GeiserX/genieacs-mcp/commit/577306d78190622eee97e362b042a69499ef373f","tags":["x_refsource_MISC"],"url":"https://github.com/GeiserX/genieacs-mcp/commit/577306d78190622eee97e362b042a69499ef373f"},{"name":"https://github.com/GeiserX/genieacs-mcp/releases/tag/v0.3.2","tags":["x_refsource_MISC"],"url":"https://github.com/GeiserX/genieacs-mcp/releases/tag/v0.3.2"}],"affected":[{"vendor":"GeiserX","product":"genieacs-mcp","versions":[{"version":"< 0.3.2","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-08-25T18:03:34.701Z"},"descriptions":[{"lang":"en","value":"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."}],"source":{"advisory":"GHSA-cmwv-wf9p-p8wx","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/GeiserX/genieacs-mcp/security/advisories/GHSA-cmwv-wf9p-p8wx","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-25T18:24:35.743227Z","id":"CVE-2026-55637","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-25T18:24:42.746Z"}}]}}