Upstream information

CVE-2026-55637 at MITRE

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.

SUSE information

Overall state of this security issue: Resolved

This issue is currently rated as having important severity.

CVSS v4 Scores
CVSS detail CNA (GitHub)
Base Score 8.8
Vector 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
Attack Vector Network
Attack Complexity Low
Attack Requirements Present
Privileges Required None
User Interaction Passive
Vulnerable System Confidentiality Impact High
Vulnerable System Integrity Impact High
Vulnerable System Availability Impact None
Subsequent System Confidentiality Impact High
Subsequent System Integrity Impact High
Subsequent System Availability Impact None
CVSSv4 Version 4.0
No SUSE Bugzilla entries cross referenced.

No SUSE Security Announcements cross referenced.

List of released packages

Product(s) Fixed package version(s) References


SUSE Timeline for this CVE

CVE page created: Fri Sep 4 16:49:07 2026
CVE page last modified: Tue Sep 8 16:49:37 2026