Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
AV AC PR UI S C I A CVSS EPSS %ile KEV N L N N U N N H 7.5 .0049 40.1 —
AFFECTED Product Versions Fixed netty >= 4.2.0.Alpha1, < 4.2.13.Final – — netty-codec-mqtt >= 4.2.0.Alpha1, < 4.2.13.Final – —
TIMELINE May 5 Reserved by GitHub_M May 13 Published (CNA: GitHub_M) Aug 3 RESCORED — CVE-2026-44248 (netty). CVSS 5.3 → 7.5 (NVD).
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.
| Date | Event | Detail |
|---|---|---|
| May 5, 2026 | Reserved | Reserved by GitHub_M |
| May 13, 2026 | Published | Published (CNA: GitHub_M) |
| August 3, 2026 | RESCORED | RESCORED — CVE-2026-44248 (netty). CVSS 5.3 → 7.5 (NVD). |
Authoritative record: CVE-2026-44248 at cve.org
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-44248 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.