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

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-20038
StatePUBLISHED
Assignercisco
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-07 17:16:54 UTC
Updated2026-10-08 20:08:45 UTC
DescriptionA 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.

Risk And Classification

Primary CVSS: v3.1 5.8 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

EPSS: 0.003010000 probability, percentile 0.209970000 (date 2026-10-09)

Problem Types: CWE-284 | CWE-284 Improper Access Control

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary5.8MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
3.1CNACVSSV3_15.8MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(1g) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(2e) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(2f) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(2g) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(2h) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(3f) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(3e) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(3g) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(4d) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(4e) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(5c) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(5d) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(1g) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(5e) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(4f) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(6e) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(6h) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(1j) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(6g) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(7f) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(7g) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(2h) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(8d) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(2j) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(8e) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(3d) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(3e) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(8f) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(8g) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.3(1d) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(8h) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(4c) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.3(2a) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.2(8i) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(5h) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.3(2b) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(3g) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(5j) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.3(2c) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(6c) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.3(2d) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.1(1f) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(7e) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(8e) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.3(2e) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(8f) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.1(2f) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.1(2g) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 15.3(2f) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(9c) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.1(3f) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(9d) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(6h) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(8h) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.1(3g) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(9e) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.1(4h) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.1(5e) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.2(1g) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.0(9f) Not specified
CNA Cisco Cisco NX-OS System Software In ACI Mode affected 16.2(2e) Not specified

References

ReferenceSourceLinkTags
sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aci-ep... [email protected] sec.cloudapps.cisco.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

Exploits

CNA: The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

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