CVE-2026-20212: critical vulnerability in Cisco NX-OS Software
Cisco Nexus 3000 and 9000 Series Switches Silicon One Hardware Abstraction Layer Remote Code Execution Vulnerability
Published · Updated
48Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 9.8epss 0.7%
from disclosure to weapon1 days
Published on NVDSep 2
1st PoC+1d
exploitation probability
0.7%top 47% of all CVEs
observed exploitation
nono source reports it
1 public exploit(s)
A vulnerability in the Silicon One integration for Cisco Nexus 9000 Series Switches could allow an unauthenticated, remote attacker to execute code with root privileges.
This vulnerability exists because TCP ports 43210 and 43211 are accessible in the default Layer 3 (L3) virtual routing and forwarding (VRF). A successful exploit could allow the attacker to connect to an affected device and send crafted input that could be executed as code with root privileges. The exploitation of this vulnerability could also cause the S1HAL process to crash, which could cause the device to reload.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
Cisco · Cisco NX-OS Softwarepublic PoCs found — 1
githubgithub.com/HORKimhab/CVE-2026-20212★ 1⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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