All vulnerabilities
CVE-2026-20349

Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection Vulnerability

Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Network & edge
Open in ThreatlineRecord JSON
CVSS
8.6High
ExploitationExploited in the wildAdded to KEV 11 Aug 2026CISA KEV
Exploit odds (EPSS)1.01%Chance of exploitation activity in the next 30 days, higher than 62% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Federal deadline14 Aug 2026Remediation due date for US federal agenciesCISA KEV
CISA required actionApply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines. CISA KEV

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

Timeline

  1. 11 Aug 2026Added to CISA KEVCISA KEV
  2. 11 Aug 2026, 17:06 UTCPublishedCVE List

Description

Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) contain a heap inspection vulnerability that could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition.

Text from CVE List

Affected versions 60

  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.1CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.1.28CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.2CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.2.3CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.2.7CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.2.11CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.2.13CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.2.14CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.3.3CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.3CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.3.14CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.18.1CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.3.15CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.18.1.3CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.18.2CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.3.19CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.3.23CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.18.2.5CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.4CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.18.2.7CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.19.1CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.4.9CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.18.2.8CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.4.14CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.18.3CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.19.1.5CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.4.18CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.19.1.9CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.18.3.39CVE List
  • Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected: 9.16.4.19CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.0.0CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.0.0.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.0.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.0.1.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.0.2CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.2.0CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.0.2.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.0.3CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.2.0.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.0.4CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.2.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.0.5CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.3.0CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.2.2CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.2.3CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.3.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.2.4CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.0.6CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.2.5CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.2.4.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.3.1.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.4.0CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.0.6.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.2.5.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.4.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.2.6CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.0.6.2CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.4.1.1CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.2.7CVE List
  • Cisco Secure Firewall Threat Defense (FTD) Softwareaffected: 7.2.5.2CVE List

References 3