Resource exhaustion in Netty - CVE-2026-50560

Vulnerability identifier: #VU133913

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-2026-50560

CWE-ID: CWE-400

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 improper handling of SETTINGS_MAX_HEADER_LIST_SIZE in the netty http/2 codec when processing http/2 requests with a client-supplied maximum header list size setting. A remote attacker can send specially crafted http/2 requests to cause a denial of service.

The issue is similar in effect to the HTTP/2 Rapid Reset attack but has a different on-the-wire signature.

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 Server 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Package Hub 15
Development Tools Module
IBM SPSS Analytic Server
IBM Maximo Application Suite - Manage Component
webMethods developer portal
webMethods ControlPlane
netty-tcnative
netty-tcnative-debugsource
netty-javadoc
netty

Install security update from vendor's website.

Netty - addressed in versions 4.1.135, 4.2.15
IBM Maximo Application Suite - Manage Component - addressed in versions 9.0.28, 9.1.20, 9.2.1
webMethods developer portal - update to 11.1 Fix14
webMethods ControlPlane - update to 11.1 Fix11
netty-tcnative - update to 2.0.79-150200.3.45.1
netty-tcnative-debugsource - update to 2.0.79-150200.3.45.1
netty-javadoc - update to 4.1.135-150200.4.50.1
netty - update to 4.1.135-150200.4.50.1

• https://github.com/netty/netty/security/advisories/GHSA-563q-j3cm-6jxm

• Multiple vulnerabilities in Netty
• Multiple vulnerabilities in IBM SPSS Analytic Server
• SUSE update for netty, netty-tcnative
• IBM Maximo Application Suite - Manage Component update for Netty
• Multiple vulnerabilities in IBM webMethods API Management