cPanel cPanel/WHM (perl-YAML-Syck): Schwachstelle ermöglicht Codeausführung und DoS
WID-SEC-2026-0939 · first 01.04.2026 · updated 28.07.2026 · CVSS 9,1
What it is about
cPanel ist eine Software für die Verwaltung von Webhosting Auftritten. Die Software ermöglicht es dem Endanwender, Statistiken einzusehen, neue Benutzeraccounts anzulegen, Maileinstellungen zu verändern und vieles mehr. Ein entfernter, anonymer Angreifer kann eine Schwachstelle in cPanel cPanel/WHM ausnutzen, um potenziell beliebigen Code auszuführen oder einen Denial-of-Service-Zustand zu verursachen.
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
- potenziell beliebigen Code auszuführen oder einen Denial-of-Service-Zustand zu verursachen
Am I affected?
Affected according to the BSI:
- Debian Linux
- Amazon Linux 2
- Red Hat Enterprise Linux
- SUSE openSUSE
- cPanel cPanel/WHM <110.0.93
- cPanel cPanel/WHM <126.0.50
- cPanel cPanel/WHM <134.0.13
- cPanel cPanel/WHM <136.0.0
- cPanel cPanel/WHM <136.0.14
- cPanel cPanel/WHM <134.0.30
- cPanel cPanel/WHM 126.0.63
- cPanel cPanel/WHM <137.9999.96
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
Update to at least:
- cPanel cPanel/WHM 110.0.93
- cPanel cPanel/WHM 126.0.50
- cPanel cPanel/WHM 134.0.13
- cPanel cPanel/WHM 136.0.0
- cPanel cPanel/WHM 136.0.14
- cPanel cPanel/WHM 134.0.30
- cPanel cPanel/WHM 137.9999.96
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)
- cPanel & WHM Change Log vom 2026-03-31 docs.cpanel.net
- cPanel & WHM Change Log vom 2026-03-31 docs.cpanel.net
- cPanel & WHM Change Log vom 2026-03-31 docs.cpanel.net
- Amazon Linux Security Advisory ALAS2-2026-3216 vom 2026-04-01 alas.aws.amazon.com
- Red Hat Security Advisory RHSA-2026:6470 vom 2026-04-02 access.redhat.com
- cPanel 136 Change Log vom 2026-04-08 docs.cpanel.net
- Debian Security Advisory DLA-4525 vom 2026-04-09 lists.debian.org
- Red Hat Security Advisory RHSA-2026:8311 vom 2026-04-15 access.redhat.com
- openSUSE Security Update OPENSUSE-SU-2026:0180-1 vom 2026-05-30 lists.opensuse.org
- cPanel & WHM Change Log vom 2026-07-27 docs.cpanel.net
CVE: CVE-2026-4177
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.