SB2026022613 - Remote denial of service in Cisco Nexus 3600 and 9500-R series switching platforms



SB2026022613 - Remote denial of service in Cisco Nexus 3600 and 9500-R series switching platforms

Published: February 26, 2026

Security Bulletin ID SB2026022613
Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Adjecent network
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Use of uninitialized variable (CVE-ID: CVE-2026-20051)

The vulnerability allows a remote attacker to perform a denial of service attack.

The vulnerability exists due to improper input validation of the Ethernet VPN (EVPN) Layer 2 ingress packets. A remote attacker on the local network send specially crafted packets to the system, cause a Layer 2 Virtual eXtensible LAN (VxLAN) traffic loop and perform a denial of service attack. 


Remediation

Install update from vendor's website.