CVE-2026-85724

Moquette is a lightweight Java MQTT broker. Prior to 0.18.1, when pattern-based ACL rules are configured, AuthorizationsCollector.canDoOperation substitutes client ID and username values directly into rules containing %c or %u and then treats the result as an MQTT topic filter. A client that uses + or # in either identity can broaden the substituted filter and gain cross-tenant read and write access. A # identity can also produce an invalid filter that triggers a NullPointerException in Topic.match and disrupts session processing. This issue is fixed in version 0.18.1.

• https://github.com/moquette-io/moquette/commit/b4a98bb3f3425ece476ed073aa080c627c1239af
• https://github.com/moquette-io/moquette/releases/tag/v0.18.1
• https://github.com/moquette-io/moquette/security/advisories/GHSA-5f42-97gr-vfhq