CVE-2026-42583

⚠️ high

Summary

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

7.5

High

EPSS Score

0.0

Exploit Probability

Published Date

2026-05-13

First Seen: 2026-05-17

📊 Relative Risk Intelligence

This CVE is Moderate Risk - more severe than 69.0% of all 328,009 vulnerabilities in our database.

#101,817

Above average severity

Severity Percentile

🎯 CISA SSVC Assessment Updated: May 14, 2026

🔍 Exploitation Status

Poc

Proof-of-concept available

⚙️ Automatable

YES

Can be exploited automatically

💥 Technical Impact

Partial

Limited system impact

SSVC data provided by CISA

Last Modified 2026-05-18

Source NVD 🔗

CVSS Vector 3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE IDs (Weakness Types)

CWE-400 CWE-770

📦 Affected Products 2

Vendor	Product	Status	Affected Versions
netty	netty	Affected	< 4.1.133
netty	netty	Affected	> 4.2.0 < 4.2.13

🔗 References 1

https://github.com/netty/netty/security/advisories/G...

Exploit Vendor Advisory

🔗 Related CVEs 6

CVE ID	Severity	CVSS	EPSS	Summary	Published
CVE-2026-44892	⚠️ high	7.5	0.5	Netty is a network application framework for development of protocol servers and clients. Prior to version 4.2.15.Final,...	2026-06-12
CVE-2026-44893	⚠️ high	7.5	0.6	Netty is a network application framework for development of protocol servers and clients. In netty-codec-haproxy prior t...	2026-06-12
CVE-2026-44894	⚠️ high	7.5	0.2	Netty is a network application framework for development of protocol servers and clients. NoQuicTokenHandler is the toke...	2026-06-12
CVE-2026-45416	⚠️ high	7.5	0.6	Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Fina...	2026-06-12
CVE-2026-45536	🔶 medium	4.0	0.2	Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Fina...	2026-06-12
CVE-2026-45673	🔶 medium	6.8	0.4	Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Fina...	2026-06-12

These CVEs affect the same products