What is the CVSS score of CVE-2026-20033?

CVE-2026-20033 has a CVSS 3.1 base score of 7.4 (High). CVSS vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H. EPSS exploitation probability: 0.0%.

Which versions of Cisco are affected by CVE-2026-20033?

Cisco Nexus 9000 Series switches running ACI mode are vulnerable to denial-of-service attacks that force device reloads, potentially disrupting network fabric operations and connected services.

How to fix or mitigate CVE-2026-20033?

Within 24 hours: Inventory all Nexus 9000 switches in ACI mode and assess criticality of each. Within 7 days: Implement network segmentation to restrict management access and monitor for suspicious activity; enable enhanced logging on affected devices. Within 30 days: Establish vendor communication protocol for patch availability and develop change management plan for deployment once patches release.

Cisco CVE-2026-20033

HIGH

Buffer Access with Incorrect Length Value (CWE-805)

2026-02-25 psirt@cisco.com

Denial Of Service Cisco

7.4

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.4 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Adjacent

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:55 vuln.today

CVE Published

Feb 25, 2026 - 17:25 nvd

HIGH 7.4

DescriptionCVE.org

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.

AnalysisAI

Cisco Nexus 9000 Series Fabric Switches in ACI mode contains a vulnerability that allows attackers to cause the device to reload unexpectedly, resulting in a DoS condition (CVSS 7.4).

Unlock full vulnerability intelligence

Risk assessment & exploitation conditions
Attack chain visualization
Remediation with exact patch versions
Threat intelligence from 22 sources
Personal watchlist & email alerts

Continue with Google Continue with GitHub

Free forever · No credit card required

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access

Send crafted Ethernet frame to management interface

Exploit

Trigger insufficient validation in frame processor

Execution

Cause unexpected device reload

Impact

Denial of service

Access

Send crafted Ethernet frame to management interface

Exploit

Trigger insufficient validation in frame processor

Execution

Cause unexpected device reload

Impact

Denial of service

Vulnerability AssessmentAI

Exploitation	Direct network access to out-of-band (OOB) management interface of Cisco Nexus 9000 Series Switch in ACI mode. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment	CVSS 7.4 (HIGH). … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	An attacker without authentication could exploit this vulnerability to cause the device to reload unexpectedly, resulting in a DoS condition.
Remediation	Monitor vendor advisories for a patch. Detailed patch versions, workarounds, and compensating controls in full report.