CVE-2026-49186
CriticalCVSS 9.8Exploitation Probability (EPSS)
Low risk24th percentile - higher than 24% of all known CVEs
Summary
The local MQTT broker does not enforce topic-level Access Control Lists (ACLs). Any client can subscribe using wildcard characters (# or +) to enumerate hidden network devices or publish rogue control commands.
Risk Assessment
An attacker can access sensitive data from network devices or send rogue commands, potentially disrupting system operation.
Recommendation
Configure topic-level ACLs for MQTT or update the broker to a patched version.
Other vulnerabilities in MQTT broker
See all- CVE-2026-44091Critical
An unauthenticated remote attacker can post a malicious ID to the MQTT Broker, resulting in the creation of a new configuration entry in the system configuration. This may lead to integrity and availability loss.
- CVE-2026-44090Critical
Missing authentication in the MQTT broker allows an unauthenticated remote attacker to access the broker, which is only protected from external access by a firewall. This may lead to full compromise of the device.
- CVE-2026-49198Medium
Improper access control in the MQTT broker allows wildcard topic subscriptions, exposing all MQTT traffic to unauthorized actors.
Original NVD description (English source)
The local MQTT broker does not enforce topic-level Access Control Lists (ACLs). This allows any client to subscribe using wildcard characters (# or +) to enumerate hidden network devices or publish rogue control commands.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS