CVE-2026-55637

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Source
https://cve.org/CVERecord?id=CVE-2026-55637
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55637.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-55637
Aliases
Downstream
Related
Published
2026-08-25T18:03:34Z
Modified
2026-10-28T02:31:13Z
Severity
  • 8.8 (High) CVSS_V4 - 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 CVSS Calculator
Summary
genieacs-mcp: DNS rebinding reaches local GenieACS MCP Streamable HTTP transport
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.

Database specific 
{
    "cna_assigner":  "GitHub_M",
    "cwe_ids":  [
        "CWE-346"
    ],
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55637.json"
}
References

Affected packages

Git / github.com/geiserx/genieacs-mcp

Affected ranges

Type
GIT
Repo
https://github.com/geiserx/genieacs-mcp
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
6455588e54cbbc32742852c652c35def6fa605c6
Fixed
577306d78190622eee97e362b042a69499ef373f
Database specific
Show details 
{
    "extracted_events":  [
        {
            "range":  [
                {
                    "introduced":  "0"
                },
                {
                    "fixed":  "0.3.2"
                }
            ],
            "source":  "AFFECTED_FIELD",
            "strategy":  "StringRangeExpression"
        },
        {
            "range":  [
                {
                    "fixed":  "577306d78190622eee97e362b042a69499ef373f"
                }
            ],
            "source":  "REFERENCES_COMMIT"
        },
        {
            "original_tag":  "v0.3.2",
            "range":  [
                {
                    "fixed":  "6455588e54cbbc32742852c652c35def6fa605c6"
                }
            ],
            "source":  "REFERENCES_TAG"
        }
    ]
}

Affected versions

v0.*
v0.0.1
v0.0.10
v0.0.11
v0.0.2
v0.0.3
v0.0.4
v0.0.5
v0.0.6
v0.0.7
v0.0.8
v0.0.9
v0.1.0
v0.2.0
v0.3.0
v0.3.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55637.json"