---
cve: "CVE-2026-42583"
severity: "HIGH"
cvss: 7.5
epss: "43%"
vendor: "netty"
kev: false
exploited: false
published: "2026-05-13 19:17:23"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-19T06:39:29+02:00"
---

# CVE-2026-42583

> 7.5 HIGH · 🧪 PoC

## Beschreibung

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-Vektor

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

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- fb13125f135ab53203513ff603872a3abe84d38d (Commit)
- b3844c8108b42f68d56144b36d4d1ed96078a688 (Commit)

## Referenzen

- <https://github.com/netty/netty/security/advisories/GHSA-mj4r-2hfc-f8p6>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-42583) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_