SB2026022613 - Remote denial of service in Cisco Nexus 3600 and 9500-R series switching platforms
Published: February 26, 2026
Security Bulletin ID
SB2026022613
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Adjecent network
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use of uninitialized variable (CVE-ID: CVE-2026-20051)
CWE-ID: CWE-457 - Use of Uninitialized Variable
CVSSv4: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
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.