Red Hat Undertow: Schwachstelle ermöglicht Denial of Service
WID-SEC-2026-3059 · first 28.08.2026 · updated 23.09.2026 · CVSS 7,5
What it is about
Undertow ist ein Webserver, der als leichtgewichtige und flexible Lösung für moderne Webanwendungen konzipiert ist. Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Red Hat Undertow ausnutzen, um einen Denial of Service Angriff durchzuführen.
Under what conditions?
Over the network and without logging in. This is the most dangerous combination: attackers can scan reachable devices automatically.
What can happen in the worst case
An attacker could use the vulnerability to
- einen Denial of Service Angriff durchzuführen
Am I affected?
Affected according to the BSI:
- Red Hat Enterprise Linux
- Red Hat Undertow
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
Install the updates provided by the vendor; details in the sources below.
Is the vulnerability already being exploited?
None of the CVEs is in the CISA catalogue of exploited vulnerabilities. That does not mean there are no attacks, only that none are documented.
Information and sources
- Original BSI advisory (WID)
- GitHub Security Advisory GHSA-28VH-MG6P-GXG7 vom 2026-08-27 github.com
- Red Hat Customer Portal CVE-2026-5680 vom 2026-08-27 access.redhat.com
- Red Hat Security Advisory RHSA-2026:70229 vom 2026-09-22 access.redhat.com
- Red Hat Security Advisory RHSA-2026:70228 vom 2026-09-22 access.redhat.com
- Red Hat Security Advisory RHSA-2026:70277 vom 2026-09-22 access.redhat.com
CVE: CVE-2026-5680
Source: BSI warning and information service (CERT-Bund); CISA. The assessment of the conditions is my reading of the BSI text; the external pages are in their original language.