Denial of Service Vulnerability in Quarkus WebSockets by Red Hat
CVE-2026-87742

7.5HIGH

Key Information:

Vendor

Red Hat
Status
Exploit Intelligence
Red Hat Build Of Quarkus
Red Hat Enterprise Linux Ai (rhel Ai) 3
Vendor
CVE Published:
17 September 2026

What is CVE-2026-87742?

A flaw exists within the quarkus-websockets-next component that allows an attacker to exploit the system by sending a rapid stream of messages over a single connection. This leads to unbounded message buffering, as the application cannot process incoming messages quickly enough. Consequently, the heap space is quickly consumed, resulting in a java.lang.OutOfMemoryError, which causes the Java Virtual Machine to crash, effectively leading to service downtime.

References

https://access.redhat.com/security/cve/CVE-2026-87742
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2530522
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

Credit

Red Hat would like to thank Michael Read ((https://github.com/Michael-JRead)) for reporting this issue.
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