Description
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.  
Published: 2026-03-04
Score: 5.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: Unauthenticated SSH authentication bypass allowing remote login as a specified user without the private key
Action: Apply Patch
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

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.

History

Thu, 16 Apr 2026 20:15:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*

Thu, 05 Mar 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Thu, 05 Mar 2026 09:15:00 +0000

Type Values Removed Values Added
First Time appeared Cisco
Cisco adaptive Security Appliance Software
Vendors & Products Cisco
Cisco adaptive Security Appliance Software

Wed, 04 Mar 2026 17:30:00 +0000

Type Values Removed Values Added
Description 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.&nbsp;&nbsp;
Title Cisco Secure Firewall Adaptive Security Appliance SSH Partial Private Key Authentication Bypass Vulnerability
Weaknesses CWE-138
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}

Subscriptions

Cisco Adaptive Security Appliance Software
cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published:

Updated: 2026-03-05T15:49:42.424Z

Reserved: 2025-10-08T11:59:15.350Z

Link: CVE-2026-20009

cve-icon Vulnrichment

Updated: 2026-03-05T15:49:36.860Z

cve-icon NVD

Status : Analyzed

Published: 2026-03-04T18:16:14.833

Modified: 2026-04-16T20:13:12.193

Link: CVE-2026-20009

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-16T13:30:16Z

Weaknesses