CVE-2026-20106

A vulnerability in the Remote Access SSL VPN, HTTP management and MUS functionality, of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Softwa

Severity
Medium 5.3
CVSS 3.1
Remote · no auth what this means
Exploited
Not listed
EPSS
0.003
23.8th percentile
Discovered by
Vendor
Vendor-published field
Published
Mar 4, 2026
Assigned by cisco

Description

A vulnerability in the Remote Access SSL VPN, HTTP management and MUS functionality, of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to exhaust device memory resulting in a denial of service (DoS) condition requiring a manual reboot. 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 stop responding, resulting in a DoS condition.

Weakness: CWE-401

Affected products

Vendor Product Category Matched by
Cisco Cisco Adaptive Security Appliance (ASA) Check your version Firewall / NGFW cna-assigner
Cisco Cisco Firepower Threat Defense (FTD) Check your version Firewall / NGFW cna-assigner
Vendor-reported products (2)
  • Cisco · Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
  • Cisco · Cisco Secure Firewall Threat Defense (FTD) Software

Vendor advisory

cisco-sa-asaftd-vpn-m9sx6MbC

Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service Vulnerabilities

Cisco’s rating: High (advisory CVSS 8.6) · Published Mar 4, 2026

Bug IDs: CSCwo49932 , CSCwo49934 , CSCwo73886 , CSCwo73889 , CSCwo73891

The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from

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