Netty SpdySessionHandler Unbounded Streams DoS
CVE-2026-93488 Published on September 18, 2026

Io.netty/netty-codec-http: netty: denial of service via unbounded concurrent spdy streams
A flaw was found in Netty. SpdySessionHandler accepts an unlimited number of concurrent remote-initiated streams because localConcurrentStreams defaults to Integer.MAX_VALUE and the handler provides no API to change it. A remote peer can open a SPDY connection and send a large number of SYN_STREAM frames with FLAG_FIN=0, causing unbounded heap and direct memory allocation that can lead to JVM OutOfMemoryError and a denial of service.

NVD

Vulnerability Analysis

CVE-2026-93488 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Timeline

Reported to Red Hat.

Made public.

Weakness Type

Allocation of Resources Without Limits or Throttling

The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.


Products Associated with CVE-2026-93488

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

Affected Versions

Red Hat AMQ Broker 7: Red Hat AMQ Clients: Red Hat build of Apache Camel 4 for Quarkus 3: Red Hat build of Apache Camel for Spring Boot 4: Red Hat build of Apicurio Registry 3: Red Hat build of Debezium 3: Red Hat Build of Keycloak: Red Hat build of Quarkus: Red Hat Data Grid 8: Red Hat Fuse 7: Red Hat JBoss Enterprise Application Platform 7: Red Hat JBoss Enterprise Application Platform 8: Red Hat Single Sign-On 7: