A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat D…

published 2026-03-04 8 mo ago modified 2026-08-11 2 mo ago also EUVD-2026-9478

cvss: 4.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits: 0; none known

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 authenticated, adjacent attacker to exhaust memory on an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to improperly validating input by the OSPF protocol when parsing packets. An attacker could exploit this vulnerability by by sending crafted OSPF packets to an affected device. A successful exploit could allow the attacker to exhaust memory on the affected device, resulting in a DoS condition.

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 8 mo ago (2026-03-04)

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	4.3	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected products

Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
Cisco Cisco Secure Firewall Threat Defense (FTD) Software

Classification

Weakness

CWE-401 Missing Release of Memory after Effective Lifetime

References

sec.cloudapps.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ospf-ZH8PhbSW
vendor-advisory

Sources

CVE List CVE-2026-20021
NVD CVE-2026-20021

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Summary