Apache Tomcat: Schwachstelle ermöglicht Denial of Service
WID-SEC-2026-2571 · first 29.07.2026 · updated 08.10.2026 · CVSS 7,5
What it is about
Apache Tomcat ist ein Web-Applikationsserver für verschiedene Plattformen. Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Apache Tomcat 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:
- Amazon Linux 2
- Red Hat Enterprise Linux
- SUSE Linux
- SUSE openSUSE
- Apache Tomcat <11.0.25
- Apache Tomcat <10.1.58
- Apache Tomcat <9.0.121
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
Update to at least:
- Apache Tomcat 11.0.25
- Apache Tomcat 10.1.58
- Apache Tomcat 9.0.121
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)
- Apache Mailing List vom 2026-07-28 lists.apache.org
- GitHub Advisory Database vom 2026-07-28 github.com
- OSS Security Mailing List vom 2026-07-28 seclists.org
- Tomcat Vulnerabilities vom 2026-07-28 tomcat.apache.org
- Tomcat Vulnerabilities vom 2026-07-28 tomcat.apache.org
- Tomcat Vulnerabilities vom 2026-07-28 tomcat.apache.org
- Amazon Linux Security Advisory ALAS2TOMCAT9-2026-028 vom 2026-09-01 alas.aws.amazon.com
- SUSE Security Update SUSE-SU-2026:4114-1 vom 2026-09-14 lists.suse.com
- SUSE Security Update SUSE-SU-2026:4119-1 vom 2026-09-14 lists.suse.com
- openSUSE Security Update OPENSUSE-SU-2026:11759-1 vom 2026-09-14 lists.opensuse.org
- openSUSE Security Update OPENSUSE-SU-2026:11761-1 vom 2026-09-14 lists.opensuse.org
- SUSE Security Update SUSE-SU-2026:4126-1 vom 2026-09-15 lists.suse.com
- SUSE Security Update SUSE-SU-2026:4203-1 vom 2026-09-16 lists.suse.com
- SUSE Security Update SUSE-SU-2026:23710-1 vom 2026-09-16 lists.suse.com
- SUSE Security Update SUSE-SU-2026:23711-1 vom 2026-09-16 lists.suse.com
- SUSE Security Update SUSE-SU-2026:23720-1 vom 2026-09-16 lists.suse.com
- SUSE Security Update SUSE-SU-2026:23691-1 vom 2026-09-16 lists.suse.com
- SUSE Security Update SUSE-SU-2026:23700-1 vom 2026-09-16 lists.suse.com
- SUSE Security Update SUSE-SU-2026:23690-1 vom 2026-09-16 lists.suse.com
- Red Hat Security Advisory RHSA-2026:73982 vom 2026-10-01 access.redhat.com
- Red Hat Security Advisory RHSA-2026:76956 vom 2026-10-07 access.redhat.com
- Red Hat Security Advisory RHSA-2026:76952 vom 2026-10-07 access.redhat.com
CVE: CVE-2026-66299
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.