CVE-2026-20073Cisco Secure Firewall Adaptive Security Appliance Software and Cisco Secure Firewall Threat Defense Software Access Control List Bypass Vulnerability

Description

A vulnerability in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to send traffic that should be denied through an affected device. This vulnerability is due to improper error handling when an affected device that is joining a cluster runs out of memory while replicating access control rules. An attacker could exploit this vulnerability by sending traffic that should be blocked through the device. A successful exploit could allow the attacker to bypass access controls and reach devices in protected networks.

Timeline

Scores

EPSS (exploitation in 30 days)

0.43% · top 62% of all CVEs (14 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: yes · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.8.

Affected products

• Cisco · Cisco Secure Firewall Adaptive Security Appliance (ASA) Software

  • affected 9.12.3
  • affected 9.12.1
  • affected 9.12.2
  • affected 9.12.4
  • affected 9.12.3.2
  • affected 9.12.3.7
  • affected 9.12.2.5
  • affected 9.12.3.12
  • affected 9.12.1.3
  • affected 9.12.2.4
  • affected 9.12.1.2
  • affected 9.12.2.9
  • affected 9.12.3.9
  • affected 9.12.2.1
  • affected 9.12.4.2
  • affected 9.12.4.4
  • affected 9.12.4.7
  • affected 9.12.4.8
  • affected 9.12.4.10
  • affected 9.12.4.13
  • affected 9.12.4.18
  • affected 9.12.4.24
  • affected 9.16.1
  • affected 9.12.4.26
  • affected 9.16.1.28
  • affected 9.12.4.29
  • affected 9.16.2
  • affected 9.12.4.30
  • affected 9.16.2.3
  • affected 9.12.4.35
  • affected 9.16.2.7
  • affected 9.12.4.37
  • affected 9.17.1
  • affected 9.16.2.11
  • affected 9.16.2.13
  • affected 9.12.4.39
  • affected 9.12.4.38
  • affected 9.16.2.14
  • affected 9.17.1.7
  • affected 9.12.4.40
  • and 119 more

• Cisco · Cisco Secure Firewall Threat Defense (FTD) Software

  • affected 6.4.0.1
  • affected 6.4.0.2
  • affected 6.4.0.5
  • affected 6.4.0
  • affected 6.4.0.3
  • affected 6.4.0.4
  • affected 6.4.0.6
  • affected 6.4.0.7
  • affected 6.4.0.8
  • affected 6.4.0.9
  • affected 6.4.0.10
  • affected 6.4.0.11
  • affected 6.4.0.12
  • affected 7.0.0
  • affected 7.0.0.1
  • affected 7.0.1
  • affected 7.1.0
  • affected 6.4.0.13
  • affected 7.0.1.1
  • affected 6.4.0.14
  • affected 7.1.0.1
  • affected 7.0.2
  • affected 6.4.0.15
  • affected 7.2.0
  • affected 7.0.2.1
  • affected 7.0.3
  • affected 7.1.0.2
  • affected 7.2.0.1
  • affected 7.0.4
  • affected 7.2.1
  • affected 7.0.5
  • affected 6.4.0.16
  • affected 7.3.0
  • affected 7.2.2
  • affected 7.2.3
  • affected 7.3.1
  • affected 7.1.0.3
  • affected 7.2.4
  • affected 7.0.6
  • affected 7.2.5
  • and 35 more

What to do

Exploitation: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-9470 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-20073](https://cveledger.app/badge/CVE-2026-20073.svg)](https://cveledger.app/cve/CVE-2026-20073)

Record last updated 4 Mar 2026, 18:07 UTC.