Medium severity · published Mar 4, 2026
CVE-2026-20106
A vulnerability in the Remote Access SSL VPN, HTTP management and MUS functionality, of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat…
5.3
CVSS
0.3%
EPSS
No
On KEV
Description
A vulnerability in the Remote Access SSL VPN, HTTP management and MUS functionality, of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to exhaust device memory resulting in a denial of service (DoS) condition requiring a manual reboot.
This vulnerability is due to trusting user input without validation. An attacker could exploit this vulnerability by sending crafted packets to the Remote Access SSL VPN server. A successful exploit could allow the attacker to cause the device to stop responding, resulting in a DoS condition.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 27% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software · Cisco
9.12.1; 9.12.1.2; 9.12.1.3; 9.12.2; 9.12.2.4; 9.12.2.5; +34 more · source: vendor
CS
Cisco Secure Firewall Threat Defense (FTD) Software · Cisco
6.4.0; 6.4.0.1; 6.4.0.3; 6.4.0.2; 6.4.0.4; 6.4.0.5; +34 more · source: vendor
AS
Adaptive Security Appliance Software · Cisco
9.12.1 before 9.16.4.85; 9.17.1 before 9.18.4.66; 9.19.1 before 9.20.4; 9.22.1.1 before 9.22.2.4; 9.23.1 before 9.23.1.7 · source: NVD
SF
Secure Firewall Threat Defense · Cisco
6.4.0 before 7.0.9; 7.1.0 before 7.2.11; 7.3.0 before 7.4.3; 7.6.0 before 7.6.4; 7.7.0 before 7.7.11 · source: NVD
Affected product
CS
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
Cisco
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-20106
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-20106
Vendor Advisory
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-m9sx6MbC
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