6.8

CVE-2026-20171: cisco cisco nx-os software

CVSS: 6.8v3.1MediumAwaiting analysis
Published 20-05-2026Last modified 20-05-2026
Open JSON

Vulnerability summary

CVE-2026-20171 is a medium (CVSS 6.8) vulnerability in cisco cisco nx-os software. EPSS estimates a 0.47% chance of exploitation in the next 30 days, higher than 39.3% of scored vulnerabilities.

Overall risk
27/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.8/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.47%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 20-05-2026
    PublishedVulnerability first disclosed.
  2. 20-05-2026
    Last modifiedVulnerability information updated.

Description

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 trigger BGP peer flaps, resulting in a denial of service (DoS) condition. This vulnerability is due to incorrect parsing of a transitive BGP attribute. An attacker could exploit this vulnerability by sending a crafted BGP update through an established BGP peer session. If the update propagates to an affected device, it could cause the device to drop the BGP session and flap with the BGP peer that is forwarding this update, resulting in a DoS condition.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.47%

Chance of exploitation in the next 30 days

Percentile

39%

Versus all other CVEs

30-day change

0.00 pp

From 0.47% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.47%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Cisco1 product
  • cisco nx-os software10.2(1) | 10.2(1q) | 10.2(2) | 10.2(3) | 10.2(3t) | 10.2(2a) | 10.3(1) | 10.2(4) | 10.3(2) | 10.3(3) | 10.2(5) | 10.2(3v) | 10.4(1) | 10.3(99w) | 10.2(6) | 10.3(3w) | 10.3(99x) | 10.3(3o) | 10.3(4) | 10.3(3p) | 10.3(4a) | 10.4(2) | 10.3(3q) | 10.3(5) | 10.2(7) | 10.4(3) | 10.3(3x) | 10.3(4g) | 10.5(1) | 10.2(8) | 10.3(3r) | 10.3(6) | 10.4(4) | 10.3(4h) | 10.5(2) | 10.3(7) | 10.4(5) | 10.5(3) | 10.2(9) | 10.4(4g) | 10.6(1) | 10.5(3t) | 10.3(8) | 10.4(6) | 10.5(3s) | 10.5(3e) | 10.5(3o) | 10.6(1s) | 10.5(3p)

1 vendor · 1 product

References

1 links