CVE-2026-20069

Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software VPN Web Services Client-Side Request Smuggling Vulnerability

Published Mar 4, 2026 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Description
A vulnerability in the VPN web services component of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct browser-based attacks against users of an affected device.

This vulnerability is due to improper validation of HTTP requests. An attacker could exploit this vulnerability by persuading a user to visit a website that is designed to pass malicious HTTP requests to a device that is running Cisco Secure Firewall ASA Software or Cisco Secure FTD Software and has web services endpoints supporting VPN features enabled. A successful exploit could allow the attacker to reflect malicious input from the affected device to the browser that is in use and conduct browser-based attacks, including cross-site scripting (XSS) attacks. The attacker is not able to directly impact the affected device.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
CPEs cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:* cpe:2.3:a:cisco:secure_firewall_threat_defense:*:*:*:*:*:*:*:*
Vendors & Products Cisco firepower Threat Defense Software
Type Values Removed Values Added
First Time appeared Cisco firepower Threat Defense Software
CPEs cpe:2.3:a:cisco:firepower_threat_defense_software:*:*:*:*:*:*:*:*
cpe:2.3:o:cisco:adaptive_security_appliance_software:*:*:*:*:*:*:*:*
Vendors & Products Cisco firepower Threat Defense Software
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
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A vulnerability in the VPN web services component of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct browser-based attacks against users of an affected device. This vulnerability is due to improper validation of HTTP requests. An attacker could exploit this vulnerability by persuading a user to visit a website that is designed to pass malicious HTTP requests to a device that is running Cisco Secure Firewall ASA Software or Cisco Secure FTD Software and has web services endpoints supporting VPN features enabled. A successful exploit could allow the attacker to reflect malicious input from the affected device to the browser that is in use and conduct browser-based attacks, including cross-site scripting (XSS) attacks. The attacker is not able to directly impact the affected device.
Title Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software VPN Web Services Client-Side Request Smuggling Vulnerability
Weaknesses CWE-444
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
cisco
Published
Updated
Mar 4, 2026, 8:24 PM
Reserved
Oct 8, 2025, 11:59 AM
Status
Analyzed
Published
Mar 4, 2026, 6:16 PM
Modified
Aug 11, 2026, 7:40 PM