CVE-2026-20039

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. 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.

8.6 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 4.0

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope CHANGED

References
Link Resource
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-dos-SpOFF2Re Vendor Advisory
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*

Configuration 2 (hide)

OR cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
History

16 Apr 2026, 20:01

Type Values Removed Values Added
First Time Cisco firepower Threat Defense Software
Cisco
Cisco adaptive Security Appliance Software
CPE cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
References () https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-dos-SpOFF2Re - () https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-dos-SpOFF2Re - Vendor Advisory
Summary
  • (es) Una vulnerabilidad en el servidor web VPN de Cisco Secure Firewall Adaptive Security Appliance (ASA) Software y Cisco Secure Firewall Threat Defense (FTD) Software podría permitir a un atacante remoto no autenticado causar una condición de denegación de servicio (DoS) en un dispositivo afectado. Esta vulnerabilidad se debe a una gestión de memoria ineficaz del servidor web VPN. Un atacante podría explotar esta vulnerabilidad enviando un gran número de solicitudes HTTP manipuladas a un dispositivo afectado. Un exploit exitoso podría permitir al atacante provocar que el dispositivo se reinicie, lo que resultaría en una condición de DoS.

04 Mar 2026, 18:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-03-04 18:16

Updated : 2026-04-16 20:01

NVD link : CVE-2026-20039

Mitre link : CVE-2026-20039

CVE.ORG link : CVE-2026-20039

JSON object : View

Products Affected

cisco

  • firepower_threat_defense_software
  • adaptive_security_appliance_software
CWE
CWE-244

Improper Clearing of Heap Memory Before Release ('Heap Inspection')