Unauthorized message injection via unchecked Last-Will publishing
Published Sep 23, 2026 · Updated Sep 23, 2026
Missing authorization in Moquette before 0.18.1 allows remote attackers to inject arbitrary messages into ACL-protected MQTT topics. PostOffice.publishWill sends a client-controlled Will through publish2Subscribers without calling authorizator.canWrite, unlike normal PUBLISH paths. Exploitation requires configured topic ACLs and an abnormal client disconnect; anonymous access is enabled by default.
Summary
What happened
Missing authorization in Moquette before 0.18.1 allows remote attackers to inject arbitrary messages into ACL-protected MQTT topics. PostOffice.publishWill sends a client-controlled Will through publish2Subscribers without calling authorizator.canWrite, unlike normal PUBLISH paths. Exploitation requires configured topic ACLs and an abnormal client disconnect; anonymous access is enabled by default.
The record
- CVE
- CVE-2026-95846
- Published
- Sep 23, 2026
- Updated
- Sep 23, 2026
- Vendor
- Moquette
- Product
- Moquette
- Classifications
- CWE-862, T1565.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 23, 2026CVE publishedPublication date reported by the CVE source.
- Sep 23, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.18.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Public exploit references
- GitHub Advisory Will ACL bypass proof of conceptfunctional · demonstrated
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Technologies
Your stack
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Your stack
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