CVE-2026-20039
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.
Scoring
- Severity
- HIGH
- CVSS base score
- 8.6
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- EPSS probability
- 0.36%
- CWE
- CWE-244
- Published
- 2026-03-04
- Last modified
- 2026-03-12
Affected products
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
- Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
Weakness type
Related vulnerabilities
- CVE-2026-20349 — Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service Vulnerability
- CVE-2026-48025 — nebula-mesh: Decrypted CA private key persists in heap after signing
- CVE-2025-33101 — Multiple Vulnerabilities in IBM Concert Software.
- CVE-2025-1722 — Multiple Vulnerabilities in IBM Concert Software
- CVE-2025-1719 — Multiple Vulnerabilities in IBM Concert Software
- CVE-2025-1721 — BM Concert Software Improper Clearing of Heap Memory Before Release.
- CVE-2025-36118 — IBM Storage Virtualize Information Disclosure
- CVE-2025-36083 — Multiple Vulnerabilities in IBM Concert Software.