Quarkus WebSockets-Next DoS via Unbounded Message Buffering
CVE-2026-87742 Published on September 17, 2026

Quarkus-websockets-next: denial of service (oom) in quarkus-websockets-next via unbounded message buffering
A flaw was found in quarkus-websockets-next. This vulnerability allows a remote attacker to cause a Denial of Service (DoS) by streaming messages over a single connection faster than the application can process them. Due to unbounded message buffering and a lack of read backpressure, this rapidly exhausts heap space, leading to a java.lang.OutOfMemoryError that crashes the Java Virtual Machine (JVM).

NVD

Vulnerability Analysis

CVE-2026-87742 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Timeline

Reported to Red Hat.

Made public. 8 days later.

Weakness Type

Allocation of Resources Without Limits or Throttling

The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.


Products Associated with CVE-2026-87742

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Affected Versions

Red Hat Exploit Intelligence: Red Hat build of Quarkus: Red Hat Enterprise Linux AI (RHEL AI) 3: Red Hat Enterprise Linux AI (RHEL AI) 3: Red Hat Enterprise Linux AI (RHEL AI) 3: Red Hat Enterprise Linux AI (RHEL AI) 3: