CVE-2026-42583: Netty: Lz4FrameDecoder resource exhaustion
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.
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H · CWE-400, CWE-770
Tracked companies
Mapped from the CVE’s affected-product data, NVD CPE matches, vendor advisories or package feeds. A mapping means the vendor’s software is named, not that its hosted service was exposed.
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
io.netty: netty-codecio.netty: netty-codec-compressionnetty: netty
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6 (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)