Medium severity · published Mar 4, 2026
CVE-2026-20023
A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an…
6.5
CVSS
0.2%
EPSS
No
On KEV
Description
A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, adjacent attacker to corrupt memory on an affected device, resulting in a denial of service (DoS) condition.
This vulnerability is due to memory corruption when parsing OSPF protocol packets. An attacker could exploit this vulnerability by sending crafted OSPF packets to an affected device. A successful exploit could allow the attacker to cause memory corruption causing the affected device to reboot, resulting in a DoS condition.
CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 4% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AS
Adaptive Security Appliance Software · Cisco
9.12.1; 9.12.1.2; 9.12.1.3; 9.12.2; 9.12.2.1; 9.12.2.4; +34 more · source: NVD
SF
Secure Firewall Threat Defense · Cisco
6.4.0; 6.4.0.1; 6.4.0.2; 6.4.0.3; 6.4.0.4; 6.4.0.5; +34 more · source: NVD
Affected product
AS
Adaptive Security Appliance Software
Cisco
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-20023
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-20023
Vendor Advisory
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ospf-ZH8PhbSW
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