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.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable yes

Technical Impact partial

Affected Vendors & Products

Vendors Products
Cisco
  • Adaptive Security Appliance Software
  • Secure Firewall Threat Defense

No data.

No data.

References
Link Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-vpn-dos-SpOFF2Re cve-icon cve-icon
History

Thu, 05 Mar 2026 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Thu, 05 Mar 2026 09:15:00 +0000

Type Values Removed Values Added
First Time appeared Cisco
Cisco adaptive Security Appliance Software
Cisco secure Firewall Threat Defense
Vendors & Products Cisco
Cisco adaptive Security Appliance Software
Cisco secure Firewall Threat Defense

Wed, 04 Mar 2026 17:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Cisco Adaptive Security Appliance and Firepower Threat Defense Software SSL VPN Authentication Denial of Service Vulnerability
Weaknesses CWE-244
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'}
cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published: 2026-03-04T17:17:49.841Z

Updated: 2026-03-05T15:49:08.973Z

Reserved: 2025-10-08T11:59:15.354Z

Link: CVE-2026-20039

cve-icon Vulnrichment

Updated: 2026-03-05T15:49:05.817Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-03-04T18:16:17.140

Modified: 2026-03-05T19:39:11.967

Link: CVE-2026-20039

cve-icon Redhat

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