CVE-2026-44248

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.
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*

History

21 Jul 2026, 12:18

Type Values Removed Values Added
References
  • () https://access.redhat.com/errata/RHSA-2026:41951 -

10 Jul 2026, 12:16

Type Values Removed Values Added
References
  • () https://access.redhat.com/errata/RHSA-2026:37390 -

30 Jun 2026, 03:19

Type Values Removed Values Added
CWE CWE-770
References
  • () https://access.redhat.com/security/cve/CVE-2026-44248 -
  • () https://bugzilla.redhat.com/show_bug.cgi?id=2477231 -
  • () https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-44248.json -

18 May 2026, 12:15

Type Values Removed Values Added
CPE cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
First Time Netty netty
Netty
References () https://github.com/netty/netty/security/advisories/GHSA-jfg9-48mv-9qgx - () https://github.com/netty/netty/security/advisories/GHSA-jfg9-48mv-9qgx - Vendor Advisory

13 May 2026, 19:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-05-13 19:17

Updated : 2026-07-21 12:18


NVD link : CVE-2026-44248

Mitre link : CVE-2026-44248

CVE.ORG link : CVE-2026-44248


JSON object : View

Products Affected

netty

  • netty
CWE
CWE-400

Uncontrolled Resource Consumption

CWE-770

Allocation of Resources Without Limits or Throttling