Auth bypass in Moquette
CVE-2026-95846
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.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.003 (24.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 25th percentile — 24.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000
Affected products
- Moquette
- Moquette-Io Moquette — versions < 0.18.1
Weakness classification (CWE)
References
- github.com/moquette-io/moquette/security/advisories/GHSA-5f42-97gr-vfhq (Exploit, Mitigation, Vendor Advisory)
- github.com/moquette-io/moquette/commit/f5a323fe782d1505c0097498cb22eb6ec6c96973 (Patch)
- github.com/moquette-io/moquette/releases/tag/v0.18.1 (Release Notes)
Frequently asked questions
- What is CVE-2026-95846?
- CVE-2026-95846 is a high-severity vulnerability in Moquette, classified under Missing Authorization. CVSS score: 7.5/10. Published 2026-09-23.
- How severe is CVE-2026-95846?
- High severity. CVSS v3 base score is 7.5 out of 10.