Out of Memory Flaw in Undertow Affects WebSocket Endpoints
CVE-2026-15565

7.5HIGH

Key Information:

Vendor

Red Hat
Status
Red Hat Build Of Apache Camel For Spring Boot 4
Red Hat Data Grid 8
Red Hat Fuse 7
Red Hat Jboss Enterprise Application Platform 7
Vendor
CVE Published:
11 August 2026

What is CVE-2026-15565?

A vulnerability has been identified in Undertow, where a remote attacker can exploit WebSocket endpoints associated with any @ServerEndpoint class that implements an @OnMessage method. This allows attackers to initiate a Denial of Service (DoS) by causing an out-of-memory condition using standard WebSocket handshake procedures without requiring any form of authentication. Consequently, such attacks can disrupt service availability and negatively impact users.

References

https://access.redhat.com/security/cve/CVE-2026-15565
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2490628
issue-trackingx_refsource_REDHAT

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.