An MQTT broker that runs on the Acer Connect M6E 5G Portable WiFi Router does not enforce topic‐level access control lists, allowing any client to subscribe to topics using wildcard characters. This flaw enables attackers to enumerate hidden network devices and to publish rogue control commands that can alter configuration or disrupt service. The security consequence is a loss of confidentiality and control over connected devices, potentially leading to denial of service or unauthorized configuration changes.

Acer:Connect M6E 5G Portable WiFi Router is affected. Specific firmware version information is not listed, so all currently deployed units running the bundled local MQTT broker are considered vulnerable until a later firmware update is applied.

The CVSS score of 8.6 indicates a high severity flaw. No EPSS score is available, and the vulnerability is not listed in CISA’s KEV catalog. The attack vector is inferred to be local network; any client that can reach the broker on the internal network can exploit the weakness by subscribing with wildcards or publishing commands. Because ACL enforcement is absent, the attacker can obtain broad access to topic data and issue control messages, making this a significant risk for network integrity and availability.