---
id: CVE-2026-93575
title: A flaw was found in Netty's MqttDecoder
summary: >-
  A flaw was found in Netty's MqttDecoder. An unauthenticated remote attacker
  can exploit this vulnerability by sending a specially crafted MQTT CONNECT
  packet. The decoder fails to properly validate the 'Properties Length' against
  the 'Re…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-1035
vendor: Red Hat
product: netty-codec-mqtt
affected:
  - netty-codec-mqtt (all versions)
  - netty-codec-mqtt (all versions)
  - netty-codec-mqtt (all versions)
  - jboss-eap-7/eap74-els-openjdk11-openshift-rhel8 (all versions)
  - jboss-eap-7/eap74-els-openjdk17-openshift-rhel8 (all versions)
  - jboss-eap-7/eap74-els-openjdk8-openshift-rhel8 (all versions)
  - netty-codec-mqtt (all versions)
  - netty-codec-mqtt (all versions)
published: '2026-09-18'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T15:17:23.520'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93575'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2026-93575'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2536967'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93575.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-93575'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93575'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00387
epssPercentile: 0.3269
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-22T14:18:05.993557Z'
ingestedAt: '2026-09-18T11:40:03.681Z'
---

## Overview

A flaw was found in Netty's MqttDecoder. An unauthenticated remote attacker can exploit this vulnerability by sending a specially crafted MQTT CONNECT packet. The decoder fails to properly validate the 'Properties Length' against the 'Remaining Length', allowing an attacker to bypass size limits. This leads to excessive memory and CPU consumption, resulting in a denial of service (DoS) due to an OutOfMemoryError.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat AMQ Broker 7, Red Hat build of Apache Camel for Spring Boot 4, Red Hat Fuse 7, Red Hat JBoss Enterprise Application Platform 7, Red Hat Single Sign-On 7 · no fix planned: Red Hat JBoss Enterprise Application Platform 7, Red Hat AMQ Broker 7, Red Hat build of Apache Camel for Spring Boot 4, Red Hat Fuse 7, … · updated 2026-09-22 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93575.json)