Cisco CVE-2026-20039
HIGHCVSS VectorNVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Lifecycle Timeline
3DescriptionNVD
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.
AnalysisAI
Unauthenticated remote attackers can trigger a denial of service against Cisco Secure Firewall ASA and FTD devices by sending crafted HTTP requests to the VPN web server, exploiting ineffective memory management to force device reloads. The vulnerability requires no authentication or user interaction and affects all network-exposed instances. …
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RemediationAI
Within 24 hours: Inventory all Cisco ASA and FTD appliances and assess internet-facing VPN exposure. Within 7 days: Implement network segmentation and access controls to restrict VPN portal access to known IP ranges, and enable detailed logging for anomaly detection. …
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