VulnerabilityAnalyzed
CVE-2026-42583
This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
HIGH 7.5EPSS 0.46%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.46%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.46% probability · 39th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-400, CWE-770
- Affected
- netty/netty
- Source
- security-advisories@github.com
References
- https://github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6Exploit, Vendor Advisory
- https://github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6Exploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.