CVE-2026-85058: Moquette-Io Moquette

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

Moquette is a lightweight Java MQTT broker. Prior to 0.18.1, PostOffice.publishWill publishes a client-controlled Last Will message through publish2Subscribers without invoking the authorizator.canWrite check used by normal PUBLISH paths. When anonymous access is enabled and topic ACLs restrict writes, a remote client can set an ACL-protected topic as the Last Will Topic during CONNECT and perform an abnormal client disconnect, causing the broker to inject attacker-controlled messages into a topic for which the client lacks write permission. This issue is fixed in version 0.18.1.

Affected products

• Moquette-Io Moquette: before 0.18.1 (fixed in 0.18.1)

Published 2026-09-18. Last modified 2026-09-24.