CVE-2026-95846 Moquette publishes Last-Will messages without enforcing write authorization
An attacker can inject unauthorized messages into restricted topics by configuring a Last-Will message that bypasses write authorization checks upon disconnection.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-95846?
CVE-2026-95846 is a high-severity missing authorization vulnerability in moquette-io moquette, published on 23 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Moquette is a lightweight Java MQTT broker. Prior to 0.18.1, PostOffice.publishWill publishes a client's Last-Will message without applying the canWrite authorization and reserved-topic checks used for a normal PUBLISH. A client can configure a Will for a topic that the client is not permitted to write and cause the broker to publish the unauthorized message when the client disconnects unexpectedly. This issue allows unauthorized message injection into restricted topics. This issue is fixed in version 0.18.1.
Weakness: CWE-862
Which versions are affected by CVE-2026-95846?
It affects 1 product.
Products include Moquette Moquette.
How do I fix CVE-2026-95846?
No fix has been published for CVE-2026-95846 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-95846 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-95846 exists.
Other vulnerabilities in moquette-io moquette
- CVE-2026-85724 Moquette pattern ACL wildcard injection allows cross-tenant authorization bypass
- CVE-2026-95848 Moquette fails open when configured authentication or authorization classes cannot load
- CVE-2026-95847 Moquette client IDs can cause cross-session H2 durable-queue corruption
- CVE-2026-95842 Moquette uncaught MQTT command exceptions can terminate shared session event loops
- CVE-2026-95843 Moquette malformed shared subscriptions can crash command processing