What’s Vulnerable › Vulnerabilities

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

• 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 2026-09-29
• Weakness: CWE-674

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.

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/ca17e0be19e86d5e291f4532dfdc94616c8e0049
• 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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