CVE-2026-42583
Netty Lz4FrameDecoder is vulnerable to resource exhaustion
7.5
HIGH
CVSS 3.1
EPSS 0.02%
Description
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Lz4FrameDecoder allocates a ByteBuf of size decompressedLength (up to 32 MB per block) before LZ4 runs. A peer only needs a 21-byte header plus compressedLength payload bytes - 22 bytes if compressedLength == 1 - to force that allocation. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
How to fix CVE-2026-42583
To remediate CVE-2026-42583, upgrade the affected package to a fixed version below.
- —no fix listed
- —upgrade to 4.1.133.Final or later
- —upgrade to 4.2.13.Final or later
Is CVE-2026-42583 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0
- from 0, < 4.1.133.Final
- from 0, < 4.2.13.Final
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |