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High · 7.5 CVE-2026-5680 EUVD-2026-67086GHSA-28vh-mg6p-gxg7

Undertow-core: undertow: denial of service via websocket permessage-deflate processing

Published Aug 27, 2026 · Updated Nov 4, 2026 · Assigned by redhat

Vendor: Red Hat Product: Red Hat build of Apache Camel - HawtIO 4 Product: Red Hat build of Apache Camel for Spring Boot 4 Product: Red Hat Data Grid 8 Product: Red Hat Enterprise Linux 10 Product: Red Hat Enterprise Linux 8 Product: Red Hat Enterprise Linux 9 Product: Red Hat Fuse 7 Product: Red Hat JBoss Enterprise Application Platform 7 Product: Red Hat JBoss Enterprise Application Platform 8 Product: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10 Product: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8 Product: Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9 Product: Red Hat JBoss Enterprise Application Platform 8.1.8.GA Product: Red Hat JBoss Enterprise Application Platform Expansion Pack Product: Red Hat Process Automation 7 Product: Red Hat Single Sign-On 7 Package: undertow Package: undertow Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

A flaw was found in Undertow. A remote attacker could exploit this vulnerability by sending specially crafted WebSocket messages with permessage-deflate negotiated. This could lead to excessive memory consumption due to the PerMessageDeflateFunction.largerBuffer() method using exponential doubling, resulting in a Denial of Service (DoS) for the affected application.

Affected products

VendorProductAffectedFixed
Red Hat Red Hat JBoss Enterprise Application Platform 8.1.8.GA — —
Red Hat Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10 — —
Red Hat Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8 — —
Red Hat Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9 — —
Red Hat Red Hat build of Apache Camel for Spring Boot 4 — —
Red Hat Red Hat build of Apache Camel - HawtIO 4 — —
Red Hat Red Hat Data Grid 8 — —
Red Hat Red Hat Enterprise Linux 10 — —
Red Hat Red Hat Enterprise Linux 8 — —
Red Hat Red Hat Enterprise Linux 9 — —
Red Hat Red Hat Fuse 7 — —
Red Hat Red Hat JBoss Enterprise Application Platform 7 — —
Red Hat Red Hat JBoss Enterprise Application Platform 8 — —
Red Hat Red Hat JBoss Enterprise Application Platform Expansion Pack — —
Red Hat Red Hat Process Automation 7 — —
Red Hat Red Hat Single Sign-On 7 — —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

Debian

Security tracker ↗
ReleasePackageFixed inAdvisory
Debian 14 undertow No fix yet —

Ubuntu

Security tracker ↗
ReleasePackageFixed inAdvisory
Ubuntu 26.10 undertow No fix yet —
Ubuntu 26.04 LTS undertow No fix yet —
Show 5 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro 24.04 LTS undertow No fix yet —
Ubuntu Pro 22.04 LTS undertow No fix yet —
Ubuntu Pro 20.04 LTS undertow No fix yet —
Ubuntu Pro 18.04 LTS undertow No fix yet —
Ubuntu Pro 16.04 LTS undertow No fix yet —

Red Hat

Security tracker ↗
ReleasePackageFixed inAdvisory
Red Hat JBoss EAP 8 eap8-activemq-artemis +14 2.40.0-8.redhat_00024.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-apache-cxf +3 4.1.7-1.SP1_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-artemis-wildfly-integration 2.0.5-1.Final_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-bouncycastle +5 1.85.0-1.redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-cryptacular 1.2.7-1.redhat_00002.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-eap-product-conf-parent +1 801.8.0-1.GA_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-hibernate +2 6.6.54-1.Final_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-httpcomponents-asyncclient 4.1.5-5.redhat_00008.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-ironjacamar +8 3.0.22-1.Final_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-jackson-core +12 2.18.9-1.redhat_00003.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-jakarta-xml-bind-api 4.0.5-1.redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-jaxb +9 4.0.7-4.redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-jaxbintros 2.1.0-1.redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-jboss-logging 3.6.3-1.Final_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-jboss-remoting 5.0.31-1.SP2_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-jbossws-api 3.1.0-1.Final_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-jbossws-common-tools 2.2.0-1.Final_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-jbossws-cxf 7.4.0-1.Final_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-jbossws-jaxws-undertow-httpspi 3.0.1-1.Final_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-jbossws-spi 5.1.0-1.Final_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-jsf-impl 4.0.11-2.SP1_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-log4j 2.25.4-1.redhat_00003.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-neethi 3.2.2-1.redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-netty +14 4.1.136-1.Final_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-nimbus-jose-jwt 9.37.4-1.redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-parsson 1.1.9-1.redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-saaj-impl +1 3.0.6-1.redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-slf4j +1 2.0.18-1.redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-undertow 2.3.26-2.SP3_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-wildfly +3 8.1.8-9.GA_redhat_00006.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-wildfly-elytron +1 2.6.11-1.Final_redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-wildfly-javadocs 8.1.1-12.GA_redhat_00048.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228
Red Hat JBoss EAP 8 eap8-ws-commons-XmlSchema 2.3.2-1.redhat_00001.1.el8eap RHSA-2026:70230, RHSA-2026:70229, RHSA-2026:70228

Advisories 4

References