Adaptive Security Appliance Software
CVE-2026-20105
HIGH
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessAuthenticate to Remote Access SSL VPN
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DeliverySend crafted packets to VPN server
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ExploitTrigger unvalidated input processing
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ExecutionExhaust device memory
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ImpactCause denial of service
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2021 - Vulnerable and Outdated Components
ASVS 5.0
V15 - Secure Coding and Architecture Resource cleanup, leak prevention
|
| Exploitation Conditions | Valid VPN user credentials and active SSL VPN connection to Cisco ASA or FTD Remote Access SSL VPN server. Attacker must be authenticated and connected to the VPN service (not management or MUS interfaces). |
| Impact | CVSS 7.7 (HIGH). Attack vector: Network. Complexity: Low. Privileges required: Low. User interaction: None. Exploitation requires authentication. Exploitable via remote/network. |
| Exploit ScenarioDerived | A remote attacker (requires authentication) could exploit this vulnerability to cause the device to reload, resulting in a DoS condition. |
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Alert meAnalysisAIv1 – Mar 12, 2026
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.
Earlier versions of this analysis (1)
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. [CVSS 7.7 HIGH]
RemediationAI
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Technical ContextAI · show details
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
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Severity by source
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
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.
Executive ViewAI
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. Organizations relying on these devices for VPN access face potential business disruption, as no patch is currently available from Cisco.
Restrict VPN access through network segmentation and firewall rules to limit exposure to trusted users only; disable SSL VPN if not operationally required; implement connection limits and session timeouts to prevent resource exhaustion; monitor memory utilization and configure automated alerting thresholds; maintain VPN failover infrastructure or alternative access methods; increase monitoring frequency and establish rapid incident response procedures for DoS events.
Threat Intelligence Overview
NVD
CVE.org
EPSS
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.
Affected Products (CPE)CVE.org
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GitHub PoC
Exploit-DB