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CVE-2026-20049

HIGH CVSS 3.1: 7.7 EPSS 0.18%
Updated Apr 16, 2026
Cisco
Parameter Value
CVSS 7.7 (HIGH)
Affected Versions 7.2.0 — 9.23.1.3
Fixed In 9.18.4.66
Type CWE-131
Vendor Cisco
Public PoC No

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. An attacker could exploit this vulnerability by sending crafted GCM-encrypted IPsec traffic to an affected device.

A successful exploit could allow the attacker to cause an unexpected reload of the device, resulting in a DoS condition. To exploit this vulnerability, the attacker must have valid credentials to establish a VPN connection with the affected device.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service

CVSS Vector v3.1

Weakness Type (CWE)

Vulnerable Products 8

Configuration From (including) Up to (excluding)
Cisco Adaptive_Security_Appliance_Software
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
9.18.1 9.18.4.66
Cisco Adaptive_Security_Appliance_Software
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
9.19.1 9.20.3.20
Cisco Adaptive_Security_Appliance_Software
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
9.22.1.1 9.22.2.4
Cisco Adaptive_Security_Appliance_Software
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
9.23.1 9.23.1.3
Cisco Firepower_Threat_Defense_Software
cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
7.2.0 7.2.11
Cisco Firepower_Threat_Defense_Software
cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
7.3.0 7.4.3
Cisco Firepower_Threat_Defense_Software
cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
7.6.0 7.6.4
Cisco Firepower_Threat_Defense_Software
cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
7.7.0 7.7.10