Uncontrolled Memory Allocation in Netty - CVE-2026-42582

Vulnerability identifier: #VU130207

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-42582

CWE-ID: CWE-789

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to memory allocation with excessive size value in io.netty.handler.codec.http3.QpackDecoder#decodeHuffmanEncodedLiteral when decoding HTTP/3 QPACK literal header fields. A remote attacker can send a specially crafted HTTP/3 HEADERS frame to cause a denial of service.

The issue occurs in the non-Huffman decoding branch before the claimed literal length is verified against the available bytes in the compressed field section.

Netty
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Real Time 15
Development Tools Module
SUSE Package Hub 15
netty-tcnative-debugsource
netty-tcnative
netty
netty-javadoc

Install security update from vendor's website.

Netty - update to 4.2.13
netty-tcnative-debugsource - update to 2.0.77-150200.3.39.1
netty-tcnative - update to 2.0.77-150200.3.39.1
netty - update to 4.1.133-150200.4.46.1
netty-javadoc - update to 4.1.133-150200.4.46.1

• https://github.com/netty/netty/security/advisories/GHSA-2c5c-chwr-9hqw

• Multiple vulnerabilities in Netty
• SUSE update for netty, netty-tcnative