CVE-2026-93488

Io.netty/netty-codec-http: netty: denial of service via unbounded concurrent spdy streams

Published Sep 18, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:/a:redhat:jboss_enterprise_application_platform:8 cpe:/a:redhat:jboss_enterprise_application_platform:8.1
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:build_keycloak: cpe:/a:redhat:build_keycloak:26.4::el9
cpe:/a:redhat:build_keycloak:26.6::el9
References
Type Values Removed Values Added
CPEs cpe:/a:redhat:debezium:3 cpe:/a:redhat:debezium:3.6
References
Type Values Removed Values Added
First Time appeared Redhat apache Camel Quarkus
Redhat quarkus
CPEs cpe:/a:redhat:apache_camel_quarkus:3.33
cpe:/a:redhat:quarkus:3.27::el8
cpe:/a:redhat:quarkus:3.33::el8
Vendors & Products Redhat apache Camel Quarkus
Redhat quarkus
Type Values Removed Values Added
First Time appeared Io.netty
Io.netty netty-codec-http
Redhat build Of Apache Camel For Quarkus
Redhat build Of Apache Camel For Spring Boot
Redhat build Of Apicurio Registry
Redhat build Of Debezium 3
Redhat build Of Keycloak
Redhat build Of Quarkus
Redhat data Grid 8
Redhat fuse 7
Redhat single Sign-on
Vendors & Products Io.netty
Io.netty netty-codec-http
Redhat build Of Apache Camel For Quarkus
Redhat build Of Apache Camel For Spring Boot
Redhat build Of Apicurio Registry
Redhat build Of Debezium 3
Redhat build Of Keycloak
Redhat build Of Quarkus
Redhat data Grid 8
Redhat fuse 7
Redhat single Sign-on
Type Values Removed Values Added
CPEs cpe:/a:redhat:quarkus:3
Vendors & Products Redhat quarkus
References
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title Io.netty/netty-codec-http: netty: denial of service via unbounded concurrent spdy streams
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-770
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'}