Netty MQTT Decoder DoS via Property Length Exploit
CVE-2026-93575 Published on September 18, 2026
Io.netty/netty-codec-mqtt: netty: resource exhaustion in mqttdecoder
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.
Vulnerability Analysis
CVE-2026-93575 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
Weaknesses in this category are related to the A9 category in the OWASP Top Ten 2017.
Products Associated with CVE-2026-93575
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