CVE-2026-20023 — Out-of-bounds Write in Cisco Secure Firewall Adaptive Security Appliance Software

CWE-787 — Out-of-bounds WriteCWE-119 — Improper Restriction of Operations within the Bounds of a Memory BufferCWE-190 — Integer Overflow or WraparoundCWE-20 — Improper Input ValidationCWE-401 — Missing Release of Memory after Effective LifetimeCWE-823 — Use of Out-of-range Pointer Offset4 documents4 sources
Severity
6.1MEDIUMNVD
EPSS
0.0%
top 93.42%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
Cisco Secure Firewall Adaptive Security Appliance SoftwareCisco Secure Firewall Threat Defense Software
Timeline
PublishedMar 4

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 ex…

CVSS vector

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:HExploitability: 1.6 | Impact: 4.0

Affected Packages2 packages

🔴Vulnerability Details

2
CVEList
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↗2026-03-04
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GHSA
GHSA-c9c2-73hm-242h: A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD↗2026-03-04
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📋Vendor Advisories

1
Cisco
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software OSPF Protocol Vulnerabilities↗2026-03-04
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CVE-2026-20023 — Out-of-bounds Write in Cisco | cvebase