In Mosquitto through 1.4.12, mosquitto.db (aka the persistence file) is world readable, which allows local users to obtain sensitive MQTT topic information.
Severity
CVSS 3.0
5.5 medium
CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS
0.4% chance of exploitation in the next 30 days; higher than 29% of CVEs (scores of 2026-10-31)