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Vulnerability · Published Sep 18, 2026 · Assigned by redhat

CVE-2026-93558Io.netty/netty-codec-http: netty: unbounded per-connection queue growth in websocketserverextensionhandler leads to denial of service

High 7.5

In plain English

A high-severity security flaw in Red Hat AMQ Broker 7 from Red Hat. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 65% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)1.1%top 34.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12nettyno fix listedDEBIAN-CVE-2026-93558
Debian:13nettyno fix listedDEBIAN-CVE-2026-93558
Debian:14nettyno fix listedDEBIAN-CVE-2026-93558
Ubuntu:26.10nettyno fix listedUBUNTU-CVE-2026-93558

Affected products (as reported)

VendorProductVersions
Red Hat Red Hat Build of Apache Camel 3.33.3.SP2 see references
Red Hat Red Hat Build of Debezium 3.6 see references
Red Hat Red Hat build of Quarkus 3.27.5.SP2 see references
Red Hat Red Hat build of Quarkus 3.33.3.SP2 see references
Red Hat Red Hat AMQ Broker 7 see references
Red Hat Red Hat AMQ Clients see references
Red Hat Red Hat build of Apache Camel 4 for Quarkus 3 see references
Red Hat Red Hat build of Apache Camel for Spring Boot 4 see references
Red Hat Red Hat build of Apicurio Registry 3 see references
Red Hat Red Hat Build of Keycloak see references
Red Hat Red Hat Data Grid 8 see references
Red Hat Red Hat Fuse 7 see references
Red Hat Red Hat JBoss Enterprise Application Platform 7 see references
Red Hat Red Hat JBoss Enterprise Application Platform 8 see references
Red Hat Red Hat Single Sign-On 7 see references

Weakness: CWE-1035 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References