Resource Exhaustion Affecting netty package, versions *


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.02% (5th percentile)

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  • Snyk IDSNYK-DEBIANUNSTABLE-NETTY-16746581
  • published18 May 2026
  • disclosed13 May 2026

Introduced: 13 May 2026

NewCVE-2026-44248  (opens in a new tab)
CWE-400  (opens in a new tab)

How to fix?

There is no fixed version for Debian:unstable netty.

NVD Description

Note: Versions mentioned in the description apply only to the upstream netty package and not the netty package as distributed by Debian. See How to fix? for Debian:unstable relevant fixed versions and status.

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, the MQTT 5 header Properties section is parsed and buffered before any message size limit is applied. Specifically, in MqttDecoder, the decodeVariableHeader() method is called before the bytesRemainingBeforeVariableHeader > maxBytesInMessage check. The decodeVariableHeader() can call other methods which will call decodeProperties(). Effectively, Netty does not apply any limits to the size of the properties being decoded. Additionally, because MqttDecoder extends ReplayingDecoder, Netty will repeatedly re-parse the enormous Properties sections and buffer the bytes in memory, until the entire thing parses to completion. This can cause high resource usage in both CPU and memory. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

CVSS Base Scores

version 3.1