CVE-2026-44248
Analyzed Analyzed - Analysis Complete
BaseFortify

Publication date: 2026-05-13

Last updated on: 2026-05-18

Assigner: GitHub, Inc.

Description
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.
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Meta Information
Published
2026-05-13
Last Modified
2026-05-18
Generated
2026-05-20
EPSS Evaluated
2026-05-19
NVD
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
netty netty to 4.1.133 (exc)
netty netty From 4.2.0 (inc) to 4.2.13 (exc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-400 The product does not properly control the allocation and maintenance of a limited resource.
Attack-Flow Graph
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