CVE-2026-5680

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

Published Aug 27, 2026 CVSS 3.1 · 7.5 High EPSS 1.1% KEV · Not listed
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.

Remediation

Vendor Workaround

To mitigate this issue, configure the PerMessageDeflateHandshake to limit the maximum decompressed buffer size. This can be achieved by setting the maxDecompressedBufferSize parameter to a reasonable value (e.g., 10 MB) in the PerMessageDeflateHandshake constructor. This action may require a restart of the affected application or service to take effect.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Redhat jboss Bpms
CPEs cpe:/a:redhat:jboss_enterprise_bpms_platform:7
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:9
cpe:/a:redhat:jboss_bpms:7
cpe:/a:redhat:jboss_enterprise_application_platform:8.1
Vendors & Products Redhat jboss Enterprise Bpms Platform
Redhat jboss Bpms
Type Values Removed Values Added
CPEs cpe:/a:redhat:jboss_enterprise_application_platform:8
Type Values Removed Values Added
CPEs cpe:/a:redhat:jboss_enterprise_application_platform:8 cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el10
cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el8
cpe:/a:redhat:jboss_enterprise_application_platform:8.1::el9
References
Type Values Removed Values Added
First Time appeared Redhat build Of Apache Camel - Hawtio
Redhat build Of Apache Camel For Spring Boot
Redhat data Grid 8
Redhat jboss Enterprise Application Platform Expansion Pack
Redhat process Automation
Redhat quay 3
Redhat single Sign On
Undertow
Undertow undertow-core
Vendors & Products Redhat build Of Apache Camel - Hawtio
Redhat build Of Apache Camel For Spring Boot
Redhat data Grid 8
Redhat jboss Enterprise Application Platform Expansion Pack
Redhat process Automation
Redhat quay 3
Redhat single Sign On
Undertow
Undertow undertow-core
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 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.
Title Undertow-core: undertow: denial of service via websocket permessage-deflate processing
First Time appeared Redhat
Redhat apache Camel Hawtio
Redhat camel Spring Boot
Redhat enterprise Linux
Redhat jboss Data Grid
Redhat jboss Enterprise Application Platform
Redhat jboss Enterprise Bpms Platform
Redhat jboss Fuse
Redhat jbosseapxp
Redhat red Hat Single Sign On
Weaknesses CWE-770
CPEs cpe:/a:redhat:apache_camel_hawtio:4
cpe:/a:redhat:camel_spring_boot:4
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_enterprise_bpms_platform:7
cpe:/a:redhat:jboss_fuse:7
cpe:/a:redhat:jbosseapxp
cpe:/a:redhat:red_hat_single_sign_on:7
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat apache Camel Hawtio
Redhat camel Spring Boot
Redhat enterprise Linux
Redhat jboss Data Grid
Redhat jboss Enterprise Application Platform
Redhat jboss Enterprise Bpms Platform
Redhat jboss Fuse
Redhat jbosseapxp
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'}