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Fencer Vulns
high 7.5

CVE-2026-87742 json

Quarkus-websockets-next: denial of service (oom) in quarkus-websockets-next via unbounded message buffering

published 2026-09-17 52 d ago modified 2026-10-09 30 d ago also EUVD-2026-81675

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 55%
public exploits
0
none known

Summary

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).

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-87742 updated cvss 7.5

quarkus-websockets-next: Denial of Service (OOM) in quarkus-websockets-next via unbounded message buffering

  • Red Hat Exploit Intelligence exploit-intelligence/agent-client-rhel9
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-rocm-rhel9, rhelai3/bootc-gaudi-rhel9, rhelai3/disk-image-cuda-rhel9
    affected: workaround, no fix available, no fix planned “Will not fix”
  • Red Hat build of Quarkus 3.27.5.SP2
    fixed: vendor fix RHSA-2026:69470
  • Red Hat build of Quarkus 3.33.3.SP2
    fixed: vendor fix RHSA-2026:69440

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
52 d ago

Exploit prediction

0.76% chance of exploitation in the next 30 days, higher than 55% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 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 Quarkus 3.27.5.SP2
  • Red Hat Red Hat build of Quarkus 3.33.3.SP2
  • Red Hat Exploit Intelligence
  • Red Hat Red Hat Enterprise Linux AI (RHEL AI) 3

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.