High [CVE-2026-20049] Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software IPsec Denial of Service Vulnerability
This high-severity Cisco advisory covers CVE-2026-20049 affecting Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.12.4.7, Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.12.4.10, Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.12.4.13.
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Summary
A vulnerability in the processing of Galois/Counter Mode (GCM)-encrypted Internet Key Exchange version 2 (IKEv2) IPsec traffic of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to the allocation of an insufficiently sized block of memory. A successful exploit could al…
Affected products named by the advisory: Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.12.4.7; Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.12.4.10; Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.12.4.13; Cisco Secure Firewall Adaptive Security Appliance (ASA) Software 9.12.4.8; and 5 more.
- Scope: This vulnerability affects Cisco devices if they are running a vulnerable release of Cisco Secure Firewall ASA Software or Secure FTD Software and are configured to use GCM encryption for IPsec IKEv2.
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
Mitigation checklist
- There are no workarounds that address this vulnerability.
Official advisory · high-confidence parse· fetched 2 months ago·verify at source
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