moquette vulnerability

Moquette is a lightweight Java MQTT broker. Prior to 0.18.1, the broker does not enforce a maximum length for pending per-session message queues. When a fast publisher sends messages to a slow subscriber whose in-flight window is full, queued messages can accumulate without bound in memory or persistent storage. Remote clients can use this condition to exhaust broker resources and cause a denial of service. This issue is fixed in version 0.18.1.

Published 23 Sep 2026Updated 23 Sep 20263 sources
CVSS 8.7

What happened

Moquette is a lightweight Java MQTT broker. Prior to 0.18.1, the broker does not enforce a maximum length for pending per-session message queues. When a fast publisher sends messages to a slow subscriber whose in-flight window is full, queued messages can accumulate without bound in memory or persistent storage. Remote clients can use this condition to exhaust broker resources and cause a denial of service. This issue is fixed in version 0.18.1.

Affected versions

moquette: < 0.18.1 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.