CVE-2026-20039Cisco · Adaptive_security_appliance_software
Vulnerability data via NVD (ingested)
A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to ineffective memory management of the VPN web server. An attacker could exploit this vulnerability by sending a large number of crafted HTTP requests to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
External references
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Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common). Live host counts are a Premium feature.
vuln:CVE-2026-20039os:"Adaptive Security Appliance Software"More intel sources (5)
vuln:CVE-2026-20039vulnerabilities.cve_id: CVE-2026-20039CVE-2026-20039CVE-2026-20039"CVE-2026-20039" exploit -site:nvd.nist.gov