CVE-2026-20009
published 2026-03-04CVE-2026-20009: A vulnerability in the implementation of the proprietary SSH stack with SSH key-based authentication in Cisco Secure Firewall Adaptive Security Appliance (ASA)…
PriorityP434medium5.3CVSS 3.1
AVNACLPRNUINSUCLINAN
EPSS
0.38%
30.3th percentile
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.
Affected
87 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| cisco | adaptive_security_appliance_software | >= 9.17.1 < 9.18.4.71 | 9.18.4.71 |
| cisco | adaptive_security_appliance_software | >= 9.19.1 < 9.20.4.10 | 9.20.4.10 |
| cisco | adaptive_security_appliance_software | >= 9.22.1.1 < 9.22.2.14 | 9.22.2.14 |
| cisco | adaptive_security_appliance_software | >= 9.23.1 < 9.23.1.19 | 9.23.1.19 |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
CVSS provenance
nvdv3.15.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
vendor_cisco5.3MEDIUM
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GHSA
GHSA-fqfv-4r6p-w7m3: A vulnerability in the implementation of the proprietary SSH stack with SSH key-based authentication in Cisco Secure Firewall Adaptive Security Applia
ghsa_unreviewed·2026-03-04
CVE-2026-20009 [MEDIUM] CWE-138 GHSA-fqfv-4r6p-w7m3: A vulnerability in the implementation of the proprietary SSH stack with SSH key-based authentication in Cisco Secure Firewall Adaptive Security Applia
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
Cisco
Cisco Secure Firewall Adaptive Security Appliance Software SSH Partial Private Key Authentication Bypass Vulnerability
vendor_cisco·2026-03-04·CVSS 5.3
CVE-2026-20009 [MEDIUM] CWE-138 Cisco Secure Firewall Adaptive Security Appliance Software SSH Partial Private Key Authentication Bypass Vulnerability
Cisco Secure Firewall Adaptive Security Appliance Software SSH Partial Private Key Authentication Bypass Vulnerability
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
Cisco
Cisco Secure Firewall Adaptive Security Appliance Software SSH Partial Private Key Authentication Bypass Vulnerability
vendor_cisco·CVSS 3.1
CVE-2026-20009 Cisco Secure Firewall Adaptive Security Appliance Software SSH Partial Private Key Authentication Bypass Vulnerability
CVE-2026-20009: Cisco Secure Firewall Adaptive Security Appliance Software SSH Partial Private Key Authentication Bypass Vulnerability
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
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-03-04
Published