CVE-2026-20070
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk18th percentile - higher than 18% of all known CVEs
Summary
A vulnerability in the VPN web services component of Cisco Secure Firewall ASA and FTD Software could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a browser accessing an affected device. This is due to improper validation of user-supplied input in HTTP requests. Exploitation could allow arbitrary HTML or script execution in the context of the VPN web server.
Risk Assessment
Risk of malicious script execution in the user's browser, potentially leading to data theft or session hijacking.
Recommendation
Update ASA/FTD software to a patched version. Apply content filtering and educate users on safe browsing.
Other vulnerabilities in Cisco Secure Firewall ASA/FTD
See all- CVE-2026-20349HighActively exploited
A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall ASA and FTD Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. The issue is due to insufficient error checking when processing HTTP requests. An attacker could exploit this by sending a crafted HTTP request to the VPN service.
- CVE-2025-20362MediumActively exploited
A vulnerability in the VPN web server of Cisco Secure Firewall ASA and FTD Software allows an unauthenticated, remote attacker to access restricted URL endpoints related to remote access VPN that should be inaccessible without authentication. The issue is due to improper validation of user-supplied input in HTTP(S) requests. A successful exploit could allow access to a restricted URL without authentication.
- CVE-2025-20333CriticalActively exploited
A vulnerability in the VPN web server of Cisco Secure Firewall ASA and FTD Software allows an authenticated, remote attacker to execute arbitrary code on the device. The issue is due to improper validation of user-supplied input in HTTP(S) requests. A successful exploit could allow the attacker to execute code as root, potentially leading to full device compromise.
- CVE-2026-20021Medium
A vulnerability in the OSPF protocol of Cisco Secure Firewall ASA Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, adjacent attacker to exhaust memory on an affected device, resulting in a denial of service (DoS) condition. This is due to improper input validation when parsing OSPF packets. Crafted packets can exhaust memory and cause service disruption.
- CVE-2026-20020Medium
A vulnerability in the OSPF protocol of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, adjacent attacker to cause an affected device to reload unexpectedly, resulting in a DoS condition. If OSPF authentication is enabled, the attacker must know the secret key. This is due to insufficient input validation when processing OSPF update packets. Crafted packets can cause a buffer overflow and device reload.
- CVE-2026-20102Medium
A vulnerability in the SAML 2.0 single sign-on (SSO) feature of Cisco Secure Firewall ASA and FTD Software could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against the SAML feature and access sensitive browser-based information. This is due to insufficient input validation of HTTP parameters. Exploitation requires persuading a user to access a malicious link.
Original NVD description (English source)
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 a cross-site scripting (XSS) attack against a browser that is accessing an affected device. This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by persuading a user to follow a link to a malicious website that is designed to submit malicious input to the affected application. A successful exploit could allow the attacker to execute arbitrary HTML or script code in the browser in the context of the VPN web server.