Vulnerability in Cisco NX-OS System Software in ACI Mode

[ Description ]Official description

A vulnerability in the endpoint group (EPG) contract functionality of Cisco Nexus 9000 Series Fabric Switches in ACI Mode could allow an unauthenticated, remote attacker to bypass configured EPG contracts. This vulnerability is due to an improper control with EPG contracts. An attacker could exploit this vulnerability by sending IPv4 or IPv6 packets using UDP source and destination ports that are assigned to DHCP traffic through an affected device. A successful exploit could allow the attacker to bypass EPG contracts on the affected device.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund7 Oct 2026WID-SEC-2026-3810

  Cisco Nexus and Cisco NX-OS: Multiple vulnerabilities Translated from German

  CVE-2026-76455CVE-2026-20038CVE-2026-76471+11 more CVEs

[ References ]References

• sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aci-epgc…