Cisco NX-OS System Software up to 16.2(2e) Endpoint Group Contract Functionality access control

Summaryinfo

A vulnerability categorized as problematic has been discovered in Cisco NX-OS System Software. The affected element is an unknown function of the component Endpoint Group Contract Functionality. The manipulation results in access control. This vulnerability is known as CVE-2026-20038. It is possible to launch the attack remotely. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Cisco NX-OS System Software. Affected is an unknown functionality of the component Endpoint Group Contract Functionality. The manipulation with an unknown input leads to a access control vulnerability. CWE is classifying the issue as CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. This is going to have an impact on integrity. CVE summarizes:

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.

The advisory is shared for download at sec.cloudapps.cisco.com. This vulnerability is traded as CVE-2026-20038 since 10/08/2025. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 10/07/2026). The MITRE ATT&CK project declares the attack technique as T1068.

Upgrading eliminates this vulnerability.

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Productinfo

Type

• Router Operating System

Vendor

• Cisco

Name

• NX-OS System Software

Version

• 15.2(1g)
• 15.2(2e)
• 15.2(2f)
• 15.2(2g)
• 15.2(2h)
• 15.2(3e)
• 15.2(3f)
• 15.2(3g)
• 15.2(4d)
• 15.2(4e)
• 15.2(4f)
• 15.2(5c)
• 15.2(5d)
• 15.2(5e)
• 15.2(6e)
• 15.2(6g)
• 15.2(6h)
• 15.2(7f)
• 15.2(7g)
• 15.2(8d)
• 15.2(8e)
• 15.2(8f)
• 15.2(8g)
• 15.2(8h)
• 15.2(8i)
• 15.3(1d)
• 15.3(2a)
• 15.3(2b)
• 15.3(2c)
• 15.3(2d)
• 15.3(2e)
• 15.3(2f)
• 16.0(1g)
• 16.0(1j)
• 16.0(2h)
• 16.0(2j)
• 16.0(3d)
• 16.0(3e)
• 16.0(3g)
• 16.0(4c)
• 16.0(5h)
• 16.0(5j)
• 16.0(6c)
• 16.0(6h)
• 16.0(7e)
• 16.0(8e)
• 16.0(8f)
• 16.0(8h)
• 16.0(9c)
• 16.0(9d)
• 16.0(9e)
• 16.0(9f)
• 16.1(1f)
• 16.1(2f)
• 16.1(2g)
• 16.1(3f)
• 16.1(3g)
• 16.1(4h)
• 16.1(5e)
• 16.2(1g)
• 16.2(2e)

License

• commercial

Website

• Vendor: https://www.cisco.com/

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