CVE-2026-15565
highA flaw was found in Undertow.
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.
CVSS
7.5
7.5 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Severity source: NVD CVSS v3.1 (secalert@redhat.com)
Timeline (UTC)
Published: 2026-08-11 09:17
Modified: 2026-11-01 01:17
NVD status: Awaiting Analysis
Last synced 1 day ago
Verified against the source API 2026-11-03 07:34 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://access.redhat.com/errata/RHSA-2026:53644 secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:53806 secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:70228 secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:70229 secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:70230 secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:70277 secalert@redhat.com
- https://access.redhat.com/security/cve/CVE-2026-15565 secalert@redhat.com
- https://bugzilla.redhat.com/show_bug.cgi?id=2490628 secalert@redhat.com
Data sources
NVD CVE API 2.0 — fetched 2026-11-03 07:34 UTC · record ↗