CVE-2026-20033
Cisco NX-OS Software Denial of Service Vulnerability
A vulnerability in Cisco Nexus 9000 Series Fabric Switches in ACI mode could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to insufficient validation when processing specific Ethernet frames. An attacker could exploit this vulnerability by sending a crafted Ethernet frame to the management interface of an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. Note: Only the out-of-band (OOB) management interface is affected.
Attack profile
How easy it is to exploit
- Attack vector
- Adjacent network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Cisco NX-OS Software Denial of Service Vulnerability
A vulnerability in Cisco Nexus 9000 Series Fabric Switches in ACI mode could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to insufficient validation when processing specific Ethernet frames. An attacker could exploit this vulnerability by sending a crafted Ethernet frame to the management interface of an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. Note: Only the out-of-band (OOB) management interface is affected.
- Record
CVE-2026-20033- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H - Weakness
- CWE-805
- Updated
- 2026-11-02
EUVDEUVD-2026-8665
A vulnerability in Cisco Nexus 9000 Series Fabric Switches in ACI mode could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to insufficient validation when processing specific Ethernet frames. An attacker could exploit this vulnerability by sending a crafted Ethernet frame to the management interface of an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. Note: Only the out-of-band (OOB) management interface is affected.
- Record
EUVD-2026-8665- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-w865-j4h6-vqm4
A vulnerability in Cisco Nexus 9000 Series Fabric Switches in ACI mode could allow an...
A vulnerability in Cisco Nexus 9000 Series Fabric Switches in ACI mode could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to insufficient validation when processing specific Ethernet frames. An attacker could exploit this vulnerability by sending a crafted Ethernet frame to the management interface of an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. Note: Only the out-of-band (OOB) management interface is affected.
- Record
GHSA-w865-j4h6-vqm4- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H - Weakness
- CWE-805
- Updated
- 2026-11-02
NVD
A vulnerability in Cisco Nexus 9000 Series Fabric Switches in ACI mode could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to insufficient validation when processing specific Ethernet frames. An attacker could exploit this vulnerability by sending a crafted Ethernet frame to the management interface of an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. Note: Only the out-of-band (OOB) management interface is affected.
- Record
CVE-2026-20033- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H - Weakness
- CWE-805
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-20033 is a high vulnerability (CVSS 7.4) in Cisco Nx-os System Software In Aci Mode, published February 25, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.17%, the 6th percentile. No source names a fixed version.