CVE-2026-20038 - Vulnerability Details

- Cisco Nexus 9000 Series Fabric Switches in ACI Mode Policy-Based Redirect Endpoint Group Contract Bypass Vulnerability

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.

Published: 2026-10-07

Score: 5.8 Medium

EPSS: n/a

KEV: No

Impact:

Action:

Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Cisco

Cisco NX-OS System Software in ACI Mode

unknown

Version	Status	Constraints
`15.2(1g)`	affected	—
`15.2(2e)`	affected	—
`15.2(2f)`	affected	—
`15.2(2g)`	affected	—
`15.2(2h)`	affected	—
`15.2(3f)`	affected	—
`15.2(3e)`	affected	—
`15.2(3g)`	affected	—
`15.2(4d)`	affected	—
`15.2(4e)`	affected	—
`15.2(5c)`	affected	—
`15.2(5d)`	affected	—
`16.0(1g)`	affected	—
`15.2(5e)`	affected	—
`15.2(4f)`	affected	—
`15.2(6e)`	affected	—
`15.2(6h)`	affected	—
`16.0(1j)`	affected	—
`15.2(6g)`	affected	—
`15.2(7f)`	affected	—
`15.2(7g)`	affected	—
`16.0(2h)`	affected	—
`15.2(8d)`	affected	—
`16.0(2j)`	affected	—
`15.2(8e)`	affected	—
`16.0(3d)`	affected	—
`16.0(3e)`	affected	—
`15.2(8f)`	affected	—
`15.2(8g)`	affected	—
`15.3(1d)`	affected	—
`15.2(8h)`	affected	—
`16.0(4c)`	affected	—
`15.3(2a)`	affected	—
`15.2(8i)`	affected	—
`16.0(5h)`	affected	—
`15.3(2b)`	affected	—
`16.0(3g)`	affected	—
`16.0(5j)`	affected	—
`15.3(2c)`	affected	—
`16.0(6c)`	affected	—
`15.3(2d)`	affected	—
`16.1(1f)`	affected	—
`16.0(7e)`	affected	—
`16.0(8e)`	affected	—
`15.3(2e)`	affected	—
`16.0(8f)`	affected	—
`16.1(2f)`	affected	—
`16.1(2g)`	affected	—
`15.3(2f)`	affected	—
`16.0(9c)`	affected	—
`16.1(3f)`	affected	—
`16.0(9d)`	affected	—
`16.0(6h)`	affected	—
`16.0(8h)`	affected	—
`16.1(3g)`	affected	—
`16.0(9e)`	affected	—
`16.1(4h)`	affected	—
`16.1(5e)`	affected	—
`16.2(1g)`	affected	—
`16.0(9f)`	affected	—
`16.2(2e)`	affected	—

No data.

Vendor Product Confidence Versions

Cisco

Cisco Nx-os System Software In Aci Mode

100%

Version	Status	Scheme	Platform
`[15.2(1g),15.2(1g)]`	affected	generic	—
`[15.2(2e),15.2(2e)]`	affected	generic	—
`[15.2(2f),15.2(2f)]`	affected	generic	—
`[15.2(2g),15.2(2g)]`	affected	generic	—
`[15.2(2h),15.2(2h)]`	affected	generic	—
`[15.2(3f),15.2(3f)]`	affected	generic	—
`[15.2(3e),15.2(3e)]`	affected	generic	—
`[15.2(3g),15.2(3g)]`	affected	generic	—
`[15.2(4d),15.2(4d)]`	affected	generic	—
`[15.2(4e),15.2(4e)]`	affected	generic	—
`[15.2(5c),15.2(5c)]`	affected	generic	—
`[15.2(5d),15.2(5d)]`	affected	generic	—
`[16.0(1g),16.0(1g)]`	affected	generic	—
`[15.2(5e),15.2(5e)]`	affected	generic	—
`[15.2(4f),15.2(4f)]`	affected	generic	—
`[15.2(6e),15.2(6e)]`	affected	generic	—
`[15.2(6h),15.2(6h)]`	affected	generic	—
`[16.0(1j),16.0(1j)]`	affected	generic	—
`[15.2(6g),15.2(6g)]`	affected	generic	—
`[15.2(7f),15.2(7f)]`	affected	generic	—
`[15.2(7g),15.2(7g)]`	affected	generic	—
`[16.0(2h),16.0(2h)]`	affected	generic	—
`[15.2(8d),15.2(8d)]`	affected	generic	—
`[16.0(2j),16.0(2j)]`	affected	generic	—
`[15.2(8e),15.2(8e)]`	affected	generic	—
`[16.0(3d),16.0(3d)]`	affected	generic	—
`[16.0(3e),16.0(3e)]`	affected	generic	—
`[15.2(8f),15.2(8f)]`	affected	generic	—
`[15.2(8g),15.2(8g)]`	affected	generic	—
`[15.3(1d),15.3(1d)]`	affected	generic	—
`[15.2(8h),15.2(8h)]`	affected	generic	—
`[16.0(4c),16.0(4c)]`	affected	generic	—
`[15.3(2a),15.3(2a)]`	affected	generic	—
`[15.2(8i),15.2(8i)]`	affected	generic	—
`[16.0(5h),16.0(5h)]`	affected	generic	—
`[15.3(2b),15.3(2b)]`	affected	generic	—
`[16.0(3g),16.0(3g)]`	affected	generic	—
`[16.0(5j),16.0(5j)]`	affected	generic	—
`[15.3(2c),15.3(2c)]`	affected	generic	—
`[16.0(6c),16.0(6c)]`	affected	generic	—
`[15.3(2d),15.3(2d)]`	affected	generic	—
`[16.1(1f),16.1(1f)]`	affected	generic	—
`[16.0(7e),16.0(7e)]`	affected	generic	—
`[16.0(8e),16.0(8e)]`	affected	generic	—
`[15.3(2e),15.3(2e)]`	affected	generic	—
`[16.0(8f),16.0(8f)]`	affected	generic	—
`[16.1(2f),16.1(2f)]`	affected	generic	—
`[16.1(2g),16.1(2g)]`	affected	generic	—
`[15.3(2f),15.3(2f)]`	affected	generic	—
`[16.0(9c),16.0(9c)]`	affected	generic	—
`[16.1(3f),16.1(3f)]`	affected	generic	—
`[16.0(9d),16.0(9d)]`	affected	generic	—
`[16.0(6h),16.0(6h)]`	affected	generic	—
`[16.0(8h),16.0(8h)]`	affected	generic	—
`[16.1(3g),16.1(3g)]`	affected	generic	—
`[16.0(9e),16.0(9e)]`	affected	generic	—
`[16.1(4h),16.1(4h)]`	affected	generic	—
`[16.1(5e),16.1(5e)]`	affected	generic	—
`[16.2(1g),16.2(1g)]`	affected	generic	—
`[16.0(9f),16.0(9f)]`	affected	generic	—
`[16.2(2e),16.2(2e)]`	affected	generic	—

Found an issue or want to improve our Enrichment? You can suggest it directly by opening an issue on our dedicated GitHub repository .

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact Low

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aci-epgcbp-SfDU7NLf

History

Wed, 07 Oct 2026 19:30:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Wed, 07 Oct 2026 18:30:00 +0000

Type	Values Removed	Values Added
First Time appeared		Cisco Cisco cisco Nx-os System Software In Aci Mode
Vendors & Products		Cisco Cisco cisco Nx-os System Software In Aci Mode

Wed, 07 Oct 2026 16:30:00 +0000

Type	Values Removed	Values Added
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.
Title		Cisco Nexus 9000 Series Fabric Switches in ACI Mode Policy-Based Redirect Endpoint Group Contract Bypass Vulnerability
Weaknesses		CWE-284
References		https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aci-epgcbp-SfDU7NLf
Metrics		cvssV3_1 `{'score': 5.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N'}`

Subscriptions

Cisco Cisco Nx-os System Software In Aci Mode

MITRE

Status: PUBLISHED

Assigner: cisco

Published: 2026-10-07T16:11:55.078Z

Updated: 2026-10-07T18:05:53.253Z

Reserved: 2025-10-08T11:59:15.354Z

Link: CVE-2026-20038

Vulnrichment

Updated: 2026-10-07T18:02:43.964Z

NVD

Status : Received

Published: 2026-10-07T17:16:54.690

Modified: 2026-10-07T19:17:36.873

Link: CVE-2026-20038

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-10-07T18:30:14Z

Weaknesses

CWE-284
Improper Access Control

Tracking

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact Low

Availability Impact None

User Interaction None

Exploitation none

Automatable yes

Technical Impact partial

Subscriptions

JSON object

JSON object

JSON object

JSON object

JSON object