MikroTik RouterOS: Schwachstelle ermöglicht Denial of Service
WID-SEC-2026-4042 · first 20.10.2026 · updated 20.10.2026 · CVSS 6,5
What it is about
MikroTik RouterOS ist ein auf Linux basierendes Betriebssystem, das für MikroTik RouterBOARD Hardware und PC-Installationen entwickelt wurde und umfangreiche Routing-, Firewall- und Netzwerkverwaltungsfunktionen bietet. Ein entfernter, authentisierter Angreifer kann eine Schwachstelle in MikroTik RouterOS ausnutzen, um einen Denial of Service Angriff durchzuführen.
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
- einen Denial of Service Angriff durchzuführen
Am I affected?
Affected according to the BSI:
- MikroTik RouterOS <7.21.5
- MikroTik RouterOS <7.23.1
The installed version is usually shown under “Help → About” or in the device’s admin interface.
What helps?
Update to at least:
- MikroTik RouterOS 7.21.5
- MikroTik RouterOS 7.23.1
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-2026-112158
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.