CVE-2026-95846: CWE-862: Missing Authorization in moquette-io moquette
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.
AI Analysis
Technical Summary
Moquette, a lightweight Java MQTT broker, has a missing authorization vulnerability (CWE-862) in versions before 0.18.1. Specifically, the PostOffice.publishWill method publishes a client's Last-Will message without enforcing canWrite authorization and reserved-topic checks that normally apply to PUBLISH operations. This allows a client to set a Will message on a topic it is not authorized to write to, resulting in unauthorized message injection upon unexpected client disconnection. The vulnerability is addressed in version 0.18.1.
Potential Impact
An attacker can inject unauthorized messages into MQTT topics that are normally restricted, potentially causing misinformation or unauthorized control messages to be distributed by the broker. This could affect the integrity of MQTT communications relying on topic-based authorization.
Mitigation Recommendations
Upgrade to moquette version 0.18.1 or later, where this authorization issue in PostOffice.publishWill is fixed. No other mitigation is indicated or required according to the available data.
CVE-2026-95846: CWE-862: Missing Authorization in moquette-io moquette
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.
CVSS v4.0
Score 8.7high
Affected software
moquette-io
moquette
pkg:github/moquette-io/moquetteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Moquette, a lightweight Java MQTT broker, has a missing authorization vulnerability (CWE-862) in versions before 0.18.1. Specifically, the PostOffice.publishWill method publishes a client's Last-Will message without enforcing canWrite authorization and reserved-topic checks that normally apply to PUBLISH operations. This allows a client to set a Will message on a topic it is not authorized to write to, resulting in unauthorized message injection upon unexpected client disconnection. The vulnerability is addressed in version 0.18.1.
Potential Impact
An attacker can inject unauthorized messages into MQTT topics that are normally restricted, potentially causing misinformation or unauthorized control messages to be distributed by the broker. This could affect the integrity of MQTT communications relying on topic-based authorization.
Mitigation Recommendations
Upgrade to moquette version 0.18.1 or later, where this authorization issue in PostOffice.publishWill is fixed. No other mitigation is indicated or required according to the available data.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-09-22T16:39:45.793Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ab402daf7a7c541060ee0d4
Added to database: 09/23/2026, 16:48:26 UTC
Last enriched: 09/23/2026, 17:03:34 UTC
Last updated: 09/24/2026, 01:57:04 UTC
Views: 9
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