Zyxel Firewall: Schwachstelle ermöglicht Codeausführung
WID-SEC-2026-0316 · first 05.02.2026 · updated 06.02.2026 · CVSS 7,2
What it is about
Zyxel ist ein Hersteller von Netzwerkkomponenten, u.a. von Firewalls. Ein entfernter, authentisierter Angreifer kann eine Schwachstelle in Zyxel Firewalls ausnutzen, um beliebigen Programmcode auszuführen.
Under what conditions?
Over the network, but only with valid access (login required), for example with stolen credentials or as an insider.
What can happen in the worst case
An attacker could use the vulnerability to
- beliebigen Programmcode auszuführen
Am I affected?
Affected according to the BSI:
- Zyxel Firewall ZLD <V5.42
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
Update to at least:
- Zyxel Firewall ZLD V5.42
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
CVE: CVE-2025-11730
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.