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Vulnerabilities

Vulnerability · CVE-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) Softwar…

Published Mar 4, 2026 · catalog updated Jun 17, 2026 · adaptive security appliance software

Last checked Oct 30, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-20009. EPSS is 0.44%. Act only if a listed version of adaptive security appliance software is installed.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium5.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.44%
Remediation
Advisory link
Affected products
cpe cisco/adaptive security appliance software

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe cisco/adaptive security appliance softwareversion unspecified

How to fix CVE-2026-20009

  • No stored fix

    No vendor fix text is stored. Use the linked advisory before you change production.

  • Version check

    No version range is stored, so an installed version cannot be checked on this page.

  • Advisory

    Open the cve_org record and follow its fix.

  • Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-20009. EPSS is 0.44%. Act only if a listed version of adaptive security appliance software is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-138. EPSS 0.44%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Cisco security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 4, 2026 · NIST NVD

    Detected

    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 authenticati

  2. Jun 17, 2026 · NIST NVD

    Updated

    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 authenticati

Sources

  • CVE.orgVulnerability recordCVE-2026-20009

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-20009

    30-day exploitation probability 0.44%

    first.org
  • NIST NVDVulnerability recordCVE-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) Software could allow an unauthenticated, remote attacker to log in to a Cisco Secure Firewall ASA device and execute com

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 30, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • FIRST EPSSOct 30, 2026
  • CVE.orgOct 16, 2026
  • NIST NVDOct 15, 2026