Undertow: undertow-websockets: undertow: pre-auth dos on websocket endpoint with @serverendpoint class with any @onmessage method
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.5%
exploitation probability
0.5%top 57% of all CVEs
observed exploitation
nono source reports it
A flaw was found in Undertow. A remote attacker can cause Out of Memory on websockets endpoint without authentication on any @ServerEndpoint class that has any @OnMessage method. This allows an attacker to cause Denial of Service attack without authentication and using only a standard WebSocket handshake.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
Red Hat · Red Hat build of Apache Camel for Spring Boot 4Red Hat · Red Hat Data Grid 8Red Hat · Red Hat Fuse 7Red Hat · Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 7Red Hat · Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 8Red Hat · Red Hat JBoss Enterprise Application Platform 7.4 ELS on RHEL 9Red Hat · Red Hat JBoss Enterprise Application Platform 8Red Hat · Red Hat JBoss Enterprise Application Platform Expansion PackRed Hat · Red Hat Single Sign-On 7References
https://access.redhat.com/errata/RHSA-2026:53644https://access.redhat.com/errata/RHSA-2026:53645https://access.redhat.com/errata/RHSA-2026:53646https://access.redhat.com/errata/RHSA-2026:53806https://access.redhat.com/security/cve/CVE-2026-15565https://bugzilla.redhat.com/show_bug.cgi?id=2490628