Resource exhaustion in Cisco Nx-Os Software
CVE-2026-20173
A vulnerability in Cisco NX-OS Software could allow an unauthenticated, remote attacker to exhaust system resources, causing a denial of service (DoS) condition. This vulnerability exists because rate limiting was improperly applied to some protocols. An attacker could exploit this vulnerability by sending a high rate of UDP or TCP connections to a data plane interface on an affected device. A successful exploit could allow the attacker to cause instability to various routing and control plane protocols through some packet loss and temporary disruptions, causing a DoS condition. This DoS condition will clear without manual intervention soon after the high rate of traffic is stopped.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Cisco Nx-Os Software — versions 10.3(1), 10.3(2), 10.3(3)
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-20173?
- CVE-2026-20173 is a medium-severity vulnerability in Cisco Nx-Os Software, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.8/10. Published 2026-10-07.
- How severe is CVE-2026-20173?
- Medium severity. CVSS v3 base score is 5.8 out of 10.