Red HatCVE-2026-15565
Red Hat Undertow: denial of service
High7.5CVE-2026-15565 · Published Aug 11, 2026 · updated Sep 25, 2026
A flaw was found in Undertow. A remote attacker can cause Out of Memory on websockets endpoint without authentication on any @ServerEndpoint class that has any @OnMessage method. This allows an attacker to cause Denial of Service attack without authentication and using only a standard WebSocket handshake.
Affected versions
The source does not list versions here. See the source advisory for affected products and fixes.
Details and references
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Severity from
- the vendor (its own CVE record or advisory)
- Weakness
- CWE-120
- www.cve.org/CVERecord?id=CVE-2026-15565
- nvd.nist.gov/vuln/detail/CVE-2026-15565
- access.redhat.com/errata/RHSA-2026:53644
- access.redhat.com/errata/RHSA-2026:53645
- access.redhat.com/errata/RHSA-2026:53646
- access.redhat.com/errata/RHSA-2026:53806
- access.redhat.com/errata/RHSA-2026:70228
- access.redhat.com/errata/RHSA-2026:70229
- access.redhat.com/errata/RHSA-2026:70230
- access.redhat.com/errata/RHSA-2026:70277
- access.redhat.com/security/cve/CVE-2026-15565
- bugzilla.redhat.com/show_bug.cgi?id=2490628
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