# CVE-2026-42583: Netty: Lz4FrameDecoder resource exhaustion

> CVE-2026-42583: Netty: Lz4FrameDecoder resource exhaustion. CVSS 7.5 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-42583
Last updated: 2026-06-17T10:48:05Z

- Published: 2026-05-13 18:09 UTC · Updated: 2026-06-17 10:48 UTC · Assigner: GitHub\_M
- CVSS: 7.5 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS: 0.46%, 40th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-400, CWE-770

## 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.

## Affected vendors and products

- io.netty: netty-codec
- io.netty: netty-codec-compression
- netty: netty

## Tracked companies

- [Bitbucket](https://rewindex.com/company/bitbucket.md)
- [Confluence](https://rewindex.com/company/confluence.md)
- [Jira](https://rewindex.com/company/jira.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-42583)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-42583)
- [https://github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6](https://github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-42583 · Markdown: https://rewindex.com/cve/CVE-2026-42583.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-42583 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:49:48.944Z