CVE-2026-85724 Moquette pattern ACL wildcard injection allows cross-tenant authorization bypass

What is CVE-2026-85724?

CVE-2026-85724 is a critical authentication bypass vulnerability in moquette-io moquette, published on 23 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

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.

Weakness: CWE-863, CWE-155

Which versions are affected by CVE-2026-85724?

It affects 1 product.

Products include Moquette Moquette.

How do I fix CVE-2026-85724?

Upgrade to a fixed version.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2026-85724 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85724 exists.

Other vulnerabilities in moquette-io moquette

• CVE-2026-95848 Moquette fails open when configured authentication or authorization classes cannot load Critical 9.3
• CVE-2026-95847 Moquette client IDs can cause cross-session H2 durable-queue corruption High 8.8
• CVE-2026-95842 Moquette uncaught MQTT command exceptions can terminate shared session event loops High 8.7
• CVE-2026-95843 Moquette malformed shared subscriptions can crash command processing High 8.7
• CVE-2026-95844 Moquette deeply nested MQTT topics can cause stack exhaustion High 8.7

Sources

• CVE record
• NVD
• OSV
• How this page is made