Cisco NX-OS Software Link Layer Discovery Protocol: Schwachstelle ermöglicht Denial of Service
WID-SEC-2026-0521 · first 26.02.2026 · updated 26.02.2026 · CVSS 7,4
What it is about
Cisco NX-OS ist ein Data Center Netzwerk-Betriebssystem für virtualisierte Rechenzentren. NX-OS wurde für Ethernet Switches der Nexus Serie und Fibre Channel Storage Area Network Swiches der MDS Serie entwickelt. Ein Angreifer aus einem angrenzenden Netzwerk kann eine Schwachstelle in Cisco NX-OS ausnutzen, um einen Denial of Service Angriff durchzuführen.
Under what conditions?
The BSI does not name any particular preconditions. Exploitable remotely according to the BSI.
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:
- Cisco NX-OS Link Layer Discovery Protocol
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)
- Cisco Security Advisory cisco-sa-n3kn9k_aci_lldp_dos-NdgRrrA3 vom 2026-02-25 sec.cloudapps.cisco.com
CVE: CVE-2026-20010
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.