CVE-2026-87742 Red Hat CVE debrief

Who should care

Defenders responsible for systems using quarkus-websockets-next should assess potential exposure and impact. They should prioritize verifying exposure and assessing potential impact on systems using quarkus-websockets-next due to a Denial of Service (DoS) vulnerability. This includes reviewing system configurations, monitoring for signs of exploitation, and planning vendor-supported updates or mitigations.

Why it matters

Defenders should prioritize verifying exposure and assessing potential impact on systems using quarkus-websockets-next due to a Denial of Service (DoS) vulnerability.

• Potential Denial of Service (DoS) attack
• Heap space exhaustion leading to java.lang.OutOfMemoryError

Technical summary

The 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, leading to a java.lang.OutOfMemoryError that crashes the Java Virtual Machine (JVM). This is due to unbounded message buffering and a lack of read backpressure in quarkus-websockets-next. The vulnerability can be triggered by sending a large number of messages in a short period, causing the application to run out of heap space and resulting in a crash.

Defensive priority

Defenders should prioritize verifying exposure and assessing potential impact on systems using quarkus-websockets-next.

Recommended defensive actions

• Verify if systems using quarkus-websockets-next are exposed to this vulnerability
• Assess potential impact of a Denial of Service (DoS) attack
• Monitor for signs of exploitation
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed

Evidence notes

The vulnerability was reported by an unknown source and is tracked by CVE-2026-87742. Limited details are available about affected versions and remediation. Defenders should verify if systems using quarkus-websockets-next are exposed to this vulnerability and assess potential impact. The CVE record was published on 2026-09-17T15:16:56.137Z and has not been modified since then.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.