CVE-2026-85058 Moquette: Missing Authorization in io.moquette:moquette-broker
Remote attackers can inject messages into restricted topics via Last Will features when anonymous access is enabled, bypassing write permissions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-85058?
CVE-2026-85058 is a high-severity missing authorization vulnerability in moquette-io moquette, published on 18 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-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.
Weakness: CWE-862
Which versions are affected by CVE-2026-85058?
2 open source packages ship an affected version, including io.moquette:moquette-broker.
| Package | Affected | Fixed in |
|---|---|---|
io.moquette:moquette-broker Maven | All versions | 0.18.1 |
io.moquette:moquette-broker Maven | All versions | 0.18.1 |
How do I fix CVE-2026-85058?
Upgrade io.moquette:moquette-broker to 0.18.1 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-85058 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85058 exists.
Sources
Also known as GHSA-9jjc-fw8x-fmwx.