Medium severity · published Oct 7, 2026
CVE-2026-20038
Cisco Nexus 9000 Series Fabric Switches in ACI Mode Policy-Based Redirect Endpoint Group Contract Bypass Vulnerability
5.8
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 23% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CN
Cisco NX-OS System Software in ACI Mode · Cisco
15.2(1g); 15.2(2e); 15.2(2f); 15.2(2g); 15.2(2h); 15.2(3f); +34 more · source: vendor
Affected product
CN
Cisco NX-OS System Software in ACI Mode
Cisco
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-20038
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-20038
sec.cloudapps.cisco.com
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aci-epgcbp-SfDU7NLf
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