CVE-2026-42583 Details
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.
A resource exhaustion vulnerability has been identified in Netty versions prior to 4.2.13.Final and 4.1.133.Final. The issue arises in the Lz4FrameDecoder, which allocates a ByteBuf based on the decompressed length, potentially up to 32 MB per block, before the LZ4 decompression occurs. This allocation can be exploited by sending a 21-byte header plus a payload that exceeds the compressed length, forcing the decoder to allocate large amounts of memory. The vulnerability allows untrusted peers to send small, repeated requests that cumulatively consume significant memory resources, leading to a denial-of-service condition.
Users can upgrade to Netty versions 4.2.13.Final or 4.1.133.Final to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 14, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6 | CISA-ADP | ExploitVendor Advisory |
| https://github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6 | [email protected] | ExploitVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-400 | Uncontrolled Resource Consumption | [email protected] |
| CWE-770 | Allocation of Resources Without Limits or Throttling | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| netty netty | < 4.1.133 >= 4.2.0, < 4.2.13 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 18, 2026 | Initial Analysis | [email protected] |
| May 14, 2026 | CVE Modified | CISA-ADP |
| May 13, 2026 | New CVE Received | [email protected] |