What is 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.
The record classifies CVE-2026-20173 under weakness class CWE-770. Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 3 days ago.
Severity and exploitation probability
- CVSS v3.1 base score
- 5.8 — MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L - EPSS (FIRST)
- 0.3% probability of exploitation in the next 30 days, higher than 29.2% of all scored CVEs
- CISA KEV
- Not listed in the CISA Known Exploited Vulnerabilities catalog
- Threadlinqs priority
- 4.1/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- Published
- 2026-10-07
Is CVE-2026-20173 being exploited?
It currently carries a trending score of 42 in the Threadlinqs vulnerability feed.
Affected products and versions
- Cisco: NX-OS Software
How to fix CVE-2026-20173
No vendor patch reference has been recorded for CVE-2026-20173 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.
Threat activity tracking CVE-2026-20173
1 tracked threat in the Threadlinqs corpus references CVE-2026-20173, either in the campaign’s CVE list or as an indicator on the campaign record.
Sources
Enriched from CVE.org, FIRST EPSS. Last verified by Threadlinqs on .