Buffer Allocation Issue in Netty Framework Affecting Multiple Versions
CVE-2026-42583

7.5HIGH

Key Information:

Vendor

Netty

Status
Netty
Netty-codec
Netty-codec-compression
Vendor
CVE Published:
13 May 2026

What is CVE-2026-42583?

A potential buffer allocation issue exists in the Netty framework versions prior to 4.2.13.Final and 4.1.133.Final. The Lz4FrameDecoder can allocate a ByteBuf of significant size (up to 32 MB) before the LZ4 decompression occurs. This can be exploited by a peer, requiring only a small header and compressed payload to trigger this undesired allocation, potentially leading to resource exhaustion. Upgrading to newer versions is essential to mitigate this risk.

Affected Version(s)

netty >= 4.2.0.Alpha1, < 4.2.13.Final < 4.2.0.Alpha1, 4.2.13.Final

netty < 4.1.133.Final < 4.1.133.Final

netty-codec < 4.1.133.Final

References

https://github.com/netty/netty/security/advisories/GHSA-m...
x_refsource_CONFIRM

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.