What’s Vulnerable › Vulnerabilities

CVE-2026-95842: Moquette uncaught MQTT command exceptions can terminate shared session event loops

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-09-23 · updated 2026-09-25
• Weakness: CWE-248

Description

Moquette is a lightweight Java MQTT broker. Prior to 0.18.1, SessionEventLoop.run catches only InterruptedException, and SessionEventLoopGroup does not restart a terminated loop. An MQTT command that raises an uncaught exception can terminate an event loop shared by multiple client sessions, preventing every co-located client from processing PUBLISH, SUBSCRIBE, PUBACK, and other commands. An attacker can select client IDs that map across the available loops to disrupt session processing for the entire broker. This issue is fixed in version 0.18.1.

Affected products

• moquette-io moquette: before 0.18.1 — fixed in 0.18.1

How to fix

Upgrade to a fixed version: moquette-io moquette 0.18.1. Check the vendor advisory for mitigations.

References

• https://github.com/moquette-io/moquette/commit/86feb7c31e6fac849c465d8079d08c0e7ef01cdf
• https://github.com/moquette-io/moquette/pull/957
• https://github.com/moquette-io/moquette/releases/tag/v0.18.1
• https://github.com/moquette-io/moquette/security/advisories/GHSA-5f42-97gr-vfhq
• https://github.com/moquette-io/moquette/security/advisories/GHSA-5f42-97gr-vfhq

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