CVE-2026-85058: CWE-862: Missing Authorization in moquette-io moquette
Moquette versions prior to 0.18.1 contain a missing authorization vulnerability in the handling of Last Will messages. Specifically, the PostOffice.publishWill method publishes client-controlled Last Will messages without performing the usual authorization checks. This allows a remote client, when anonymous access is enabled and topic ACLs restrict writes, to inject messages into ACL-protected topics by setting them as the Last Will Topic and then disconnecting abnormally. The 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. The PostOffice.publishWill function publishes a client-controlled Last Will message via publish2Subscribers without invoking the authorizator.canWrite check that is normally enforced for PUBLISH operations. When anonymous access is enabled and topic ACLs restrict write permissions, a remote attacker can specify an ACL-protected topic as the Last Will Topic during the CONNECT phase. By then performing an abnormal client disconnect, the attacker causes the broker to inject messages into the protected topic, circumventing write restrictions. This vulnerability has a CVSS 3.1 score of 7.5 (high severity) and is resolved in version 0.18.1.
Potential Impact
An attacker can inject arbitrary messages into MQTT topics for which they do not have write permissions by exploiting the missing authorization check on Last Will messages. This can lead to unauthorized message injection, potentially disrupting MQTT topic integrity and trust. Confidentiality and availability are not impacted, but message integrity is compromised.
Mitigation Recommendations
Upgrade moquette to version 0.18.1 or later, where this missing authorization check vulnerability is fixed. No other mitigations are specified. Patch status is confirmed fixed in 0.18.1.
CVE-2026-85058: CWE-862: Missing Authorization in moquette-io moquette
Description
Moquette versions prior to 0.18.1 contain a missing authorization vulnerability in the handling of Last Will messages. Specifically, the PostOffice.publishWill method publishes client-controlled Last Will messages without performing the usual authorization checks. This allows a remote client, when anonymous access is enabled and topic ACLs restrict writes, to inject messages into ACL-protected topics by setting them as the Last Will Topic and then disconnecting abnormally. The issue is fixed in version 0.18.1.
CVSS v3.1
Score 7.5high
Affected software
moquette-io
moquette
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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. The PostOffice.publishWill function publishes a client-controlled Last Will message via publish2Subscribers without invoking the authorizator.canWrite check that is normally enforced for PUBLISH operations. When anonymous access is enabled and topic ACLs restrict write permissions, a remote attacker can specify an ACL-protected topic as the Last Will Topic during the CONNECT phase. By then performing an abnormal client disconnect, the attacker causes the broker to inject messages into the protected topic, circumventing write restrictions. This vulnerability has a CVSS 3.1 score of 7.5 (high severity) and is resolved in version 0.18.1.
Potential Impact
An attacker can inject arbitrary messages into MQTT topics for which they do not have write permissions by exploiting the missing authorization check on Last Will messages. This can lead to unauthorized message injection, potentially disrupting MQTT topic integrity and trust. Confidentiality and availability are not impacted, but message integrity is compromised.
Mitigation Recommendations
Upgrade moquette to version 0.18.1 or later, where this missing authorization check vulnerability is fixed. No other mitigations are specified. Patch status is confirmed fixed in 0.18.1.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-09-02T21:21:01.774Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aad792755bf5e2cf5562f9c
Added to database: 09/18/2026, 17:47:19 UTC
Last enriched: 09/18/2026, 18:01:34 UTC
Last updated: 09/18/2026, 18:43:47 UTC
Views: 6
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