What is the CVSS score of CVE-2026-20105?

CVE-2026-20105 has a CVSS 3.1 base score of 7.7 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H. EPSS exploitation probability: 0.1%.

Which versions of Adaptive Security Appliance Software are affected by CVE-2026-20105?

A high-severity vulnerability in Cisco Secure Firewall (ASA/FTD) Remote Access SSL VPN allows authenticated VPN users to crash the firewall through memory exhaustion, causing service outages.

How to fix or mitigate CVE-2026-20105?

Within 24 hours: Identify all Cisco ASA/FTD devices running affected versions and document current VPN user base and access patterns. Within 7 days: Implement network monitoring to detect abnormal memory consumption on VPN gateways; restrict VPN access to only essential users and required business functions; enable detailed logging for VPN session activity. Within 30 days: Monitor Cisco security advisories for patch release; evaluate alternative VPN solutions or backup firewall appliances; conduct tabletop exercise for VPN outage scenario.

Adaptive Security Appliance Software CVE-2026-20105

HIGH

Memory Leak (CWE-401)

2026-03-04 psirt@cisco.com

Cisco Denial Of Service Adaptive Security Appliance Software Firepower Threat Defense Software

7.7

CVSS 3.1 · Vendor: cisco

Severity by source

Vendor (cisco) PRIMARY

7.7 HIGH

AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

Primary rating from Vendor (cisco) · only source for this CVE.

CVSS VectorVendor: cisco

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Re-analysis Queued

Apr 16, 2026 - 20:37 vuln.today

cvss_changed

Analysis Generated

Mar 12, 2026 - 22:05 vuln.today

CVE Published

Mar 04, 2026 - 18:16 nvd

HIGH 7.7

DescriptionCVE.org

A vulnerability in the Remote Access SSL VPN functionality of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with a valid VPN connection to exhaust device memory resulting in a denial of service (DoS) condition.This does not affect the management or MUS interfaces. This vulnerability is due to trusting user input without validation. An attacker could exploit this vulnerability by sending crafted packets to the Remote Access SSL VPN server. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

AnalysisAI

Denial of service in Cisco Secure Firewall ASA and FTD Remote Access SSL VPN functionality allows authenticated attackers to exhaust device memory by sending specially crafted packets, forcing a device reload. The vulnerability stems from insufficient input validation on user-supplied data and requires valid VPN credentials to exploit. No patch is currently available.

Technical ContextAI

Classified as CWE-401 (Memory Leak). A vulnerability in the Remote Access SSL VPN functionality of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with a valid VPN connection to exhaust device memory resulting in a denial of service (DoS) condition.This does not affect the management or MUS interfaces. This vulnerability is due to trusting user input without validation. An attacker could exploit this vulnerability by