What is CVE-2026-20171?

CVE-2026-20171 is a medium-severity vulnerability in Cisco Nx-os Software, classified under Always-Incorrect Control Flow Implementation. CVSS score: 6.8/10. Published 2026-05-20.

How severe is CVE-2026-20171?

Medium severity. CVSS v3 base score is 6.8 out of 10.

Vulnerability in Cisco Nx-os Software

CVE-2026-20171

A vulnerability in the Border Gateway Protocol (BGP) enforce-first-as feature of Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode could allow an unauthenticated, remote attacker to tr…

EPSS: 0.000 (12.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H.

Affected products

Cisco Nx-os Software — versions 10.2(1), 10.2(1q), 10.2(2)

Weakness classification (CWE)

CWE-670 — Always-Incorrect Control Flow Implementation

References

psirt@cisco.com

Frequently asked questions

What is CVE-2026-20171?: CVE-2026-20171 is a medium-severity vulnerability in Cisco Nx-os Software, classified under Always-Incorrect Control Flow Implementation. CVSS score: 6.8/10. Published 2026-05-20.
How severe is CVE-2026-20171?: Medium severity. CVSS v3 base score is 6.8 out of 10.