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Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software SSL VPN Denial of Service Vulnerability

medcisco_psirtPublished 2026-09-16

<p><strong>Update for September 16, 2026: </strong>The original 1.0 version of this advisory was specific to the Cisco Adaptive Security Virtual Appliance (ASAv) and Cisco Secure Firewall Threat Defense Virtual (FTDv) models. However, it was later found that this vulnerability affects all Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD

Indicators of compromise

Original source: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftdvirtual-dos-MuenGnYR?vs_f=Cisco%20Security%20Advisory%26vs_cat=Security%20Intelligence%26vs_type=RSS%26vs_p=Cisco%20Secure%20Firewall%20Adaptive%20Security%20Appliance%20and%20Secure%20Firewall%20Threat%20Defense%20Software%20SSL%20VPN%20Denial%20of%20Service%20Vulnerability%26vs_k=1