What is the CVSS score of CVE-2026-20009?

CVE-2026-20009 has a CVSS 3.1 base score of 5.3 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N. EPSS exploitation probability: 0.0%.

Which versions of Cisco are affected by CVE-2026-20009?

CVE-2026-20009 presents moderate security risk rated CVSS 5.3. Exploitation could compromise the security of affected deployments.

How to fix or mitigate CVE-2026-20009?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Monitor vendor channels for patch availability.

Cisco CVE-2026-20009

MEDIUM

Improper Neutralization of Special Elements (CWE-138)

2026-03-04 psirt@cisco.com

Cisco Information Disclosure

5.3

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

5.3 MEDIUM

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:05 vuln.today

CVE Published

Mar 04, 2026 - 18:16 nvd

MEDIUM 5.3

DescriptionCVE.org

A vulnerability in the implementation of the proprietary SSH stack with SSH key-based authentication in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to log in to a Cisco Secure Firewall ASA device and execute commands as a specific user.

This vulnerability is due to insufficient validation of user input during the SSH authentication phase. An attacker could exploit this vulnerability by submitting crafted input during SSH authentication to an affected device. A successful exploit could allow the attacker to log in to the device as a specific user without the private SSH key of that user. To exploit this vulnerability, the attacker must possess a valid username and the associated public key. The private key is not required. Notes:

Exploitation of this vulnerability does not provide the attacker with root access. The authentication, authorization, and accounting (AAA) configuration command auto-enable is not affected by this vulnerability.  

AnalysisAI

Unauthenticated SSH authentication bypass in Cisco Secure Firewall ASA allows remote attackers to log in as arbitrary users by exploiting insufficient input validation during the SSH key authentication phase, requiring only knowledge of a valid username and its associated public key. This vulnerability enables attackers to execute arbitrary commands on affected ASA devices with the privileges of the compromised user account. No patch is currently available.

Technical ContextAI

in the implementation of the proprietary SSH stack with SSH key-based authentication in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to log in to a Cisco Secure Firewall ASA device and execute commands as a specific user.