A flaw was found in Netty's WebSocketServerExtensionHandler. A remote, unauthenticated attacker can exploit this vulnerability by using HTTP/1.1 pipelining to send requests faster than the application can respond. This leads to an unbounded growth of a per-connection queue, consuming excessive memory. Eventually, this can cause the Java Virtual Machine (JVM) to exhaust its heap, resulting in a Denial of Service (DoS) for the affected server.

Project Subscriptions

Vendors Products
Amq Broker Subscribe
Amq Clients Subscribe
Apicurio Registry Subscribe
Build Keycloak Subscribe
Camel Quarkus Subscribe
Camel Spring Boot Subscribe
Debezium Subscribe
Jboss Data Grid Subscribe
Jboss Enterprise Application Platform Subscribe
Jboss Fuse Subscribe
Quarkus Subscribe
Red Hat Single Sign On Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

See https://github.com/netty/netty/security/advisories/GHSA-2g37-3h88-55hc for fixed versions and remediation guidance.

History

Sat, 19 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Important


Fri, 18 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
Description Unbounded Per-Connection Queue Growth in WebSocketServerExtensionHandler Leads to Denial of Service A flaw was found in Netty's WebSocketServerExtensionHandler. A remote, unauthenticated attacker can exploit this vulnerability by using HTTP/1.1 pipelining to send requests faster than the application can respond. This leads to an unbounded growth of a per-connection queue, consuming excessive memory. Eventually, this can cause the Java Virtual Machine (JVM) to exhaust its heap, resulting in a Denial of Service (DoS) for the affected server.
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 18 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
Description Unbounded Per-Connection Queue Growth in WebSocketServerExtensionHandler Leads to Denial of Service
Title Io.netty/netty-codec-http: netty: unbounded per-connection queue growth in websocketserverextensionhandler leads to denial of service
First Time appeared Redhat
Redhat amq Broker
Redhat amq Clients
Redhat apicurio Registry
Redhat build Keycloak
Redhat camel Quarkus
Redhat camel Spring Boot
Redhat debezium
Redhat jboss Data Grid
Redhat jboss Enterprise Application Platform
Redhat jboss Fuse
Redhat quarkus
Redhat red Hat Single Sign On
Weaknesses CWE-1035
CPEs cpe:/a:redhat:amq_broker:7
cpe:/a:redhat:amq_clients:2023
cpe:/a:redhat:apicurio_registry:3
cpe:/a:redhat:build_keycloak:
cpe:/a:redhat:camel_quarkus:3
cpe:/a:redhat:camel_spring_boot:4
cpe:/a:redhat:debezium:3
cpe:/a:redhat:jboss_data_grid:8
cpe:/a:redhat:jboss_enterprise_application_platform:7
cpe:/a:redhat:jboss_enterprise_application_platform:8
cpe:/a:redhat:jboss_fuse:7
cpe:/a:redhat:quarkus:3
cpe:/a:redhat:red_hat_single_sign_on:7
Vendors & Products Redhat
Redhat amq Broker
Redhat amq Clients
Redhat apicurio Registry
Redhat build Keycloak
Redhat camel Quarkus
Redhat camel Spring Boot
Redhat debezium
Redhat jboss Data Grid
Redhat jboss Enterprise Application Platform
Redhat jboss Fuse
Redhat quarkus
Redhat red Hat Single Sign On
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-09-18T20:22:37.565Z

Reserved: 2026-09-18T09:41:56.676Z

Link: CVE-2026-93558

cve-icon Vulnrichment

Updated: 2026-09-18T14:53:49.044Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-18T15:17:19.590

Modified: 2026-09-18T21:18:46.593

Link: CVE-2026-93558

cve-icon Redhat

Severity : Important

Publid Date: 2026-09-10T00:42:37Z

Links: CVE-2026-93558 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-18T23:15:17Z

Weaknesses