Vulnerability · Published Sep 23, 2026 · Assigned by GitHub_M
CVE-2026-95842Moquette uncaught MQTT command exceptions can terminate shared session event loops
High 8.7
In plain English
A high-severity security flaw in moquette from moquette-io. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Maven | io.moquette:moquette-broker | 0.18.1 | GHSA-5f42-97gr-vfhq |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| moquette-io | moquette | < 0.18.1 |
Weakness: CWE-248 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
References
- https://github.com/moquette-io/moquette/security/advisories/GHSA-5f42-97gr-vfhq x_refsource_CONFIRM
- https://github.com/moquette-io/moquette/pull/957 x_refsource_MISC
- https://github.com/moquette-io/moquette/commit/86feb7c31e6fac849c465d8079d08c0e7ef01cdf x_refsource_MISC
- https://github.com/moquette-io/moquette/releases/tag/v0.18.1 x_refsource_MISC