Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Netty | Netty | < 4.1.133 |
Related Weaknesses (CWE)
References
- https://github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6ExploitVendor Advisory
- https://github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6ExploitVendor Advisory
FAQ
What is CVE-2026-42583?
CVE-2026-42583 is a vulnerability with a CVSS score of 7.5 (HIGH). 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) be...
How severe is CVE-2026-42583?
CVE-2026-42583 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-42583?
Check the references section above for vendor advisories and patch information. Affected products include: Netty Netty.