{"apiVersion":"1.0","identifier":"CVE-2026-55637","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.","publishedAt":"2026-08-25T18:17:56","lastModifiedAt":"2026-08-25T19:16:50","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55637","cvssScore":8.8,"cvssVector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","epssProbability":0.00205,"riskScore":0.9,"affectedProduct":"genieacs-mcp","affectedVersions":"<0.3.2","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-55637","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-55637","en":"https://www.redsauce.net/en/cves/CVE-2026-55637","fr":"https://www.redsauce.net/fr/cves/CVE-2026-55637","pt":"https://www.redsauce.net/pt/cves/CVE-2026-55637","de":"https://www.redsauce.net/de/cves/CVE-2026-55637","sk":"https://www.redsauce.net/sk/cves/CVE-2026-55637","el":"https://www.redsauce.net/el/cves/CVE-2026-55637"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-55637"}}