Multiple Vulnerabilities in Cisco Products Could Allow for Remote Code Execution

Multiple vulnerabilities have been discovered in Cisco products, the most severe of which could allow for remote code execution. 

• Cisco Secure Firewall Management Center (FMC) is a centralized management platform for Cisco firewalls.
• Cisco Secure Firewall Adaptive Security Appliance (ASA) Software is the core operating system that powers the Cisco ASA family of firewalls.
• Cisco Secure Firewall Threat Defense (FTD) is a unified software image for Cisco Firepower appliances that combines ASA firewall functionality with Snort IPS, URL filtering, and advanced malware protection (AMP).

Successful exploitation of the most severe of these vulnerabilities could allow for remote code execution as root, which may lead to the complete compromise of the affected device.

There are currently no reports of these vulnerabilities being exploited in the wild. 

Multiple vulnerabilities have been discovered in Cisco products, the most severe of which could allow for remote code execution. Details of the vulnerabilities are as follows:

Tactic: Initial Access (TA0001):

Technique: Exploit Public-Facing Application (T1190):

• A vulnerability in the web interface of Cisco Secure Firewall Management Center (FMC) Software could allow an unauthenticated, remote attacker to bypass authentication and execute script files on an affected device to obtain root access to the underlying operating system. This vulnerability is due to an improper system process that is created at boot time. An attacker could exploit this vulnerability by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to execute a variety of scripts and commands that allow root access to the device. (CVE-2026-20079)
• A vulnerability in the web-based management interface of Cisco Secure Firewall Management Center (FMC) Software could allow an unauthenticated, remote attacker to execute arbitrary Java code as root on an affected device. This vulnerability is due to insecure deserialization of a user-supplied Java byte stream. An attacker could exploit this vulnerability by sending a crafted serialized Java object to the web-based management interface of an affected device. (CVE-2026-20131)

Details of lower severity vulnerabilities:

• A vulnerability in the Remote Access SSL VPN functionality of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a DoS condition. (CVE-2026-20101)
• A vulnerability in the Remote Access SSL VPN functionality of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an unauthenticated, remote attacker to exhaust device memory, resulting in a DoS to new Remote Access SSL VPN connections. (CVE-2026-20103)
• A vulnerability in the Lua interpreter of the Remote Access SSL VPN functionality of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an authenticated, remote attacker with valid VPN credentials to cause the device to reload unexpectedly, resulting in a DoS condition. (CVE-2026-20100)
• A vulnerability in the Remote Access SSL VPN functionality of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an authenticated, remote attacker with valid VPN credentials to exhaust device memory, resulting in a denial of service (DoS) condition. (CVE-2026-20105)
• A vulnerability in the Remote Access SSL VPN, HTTP management, and MUS functionalities of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an unauthenticated, remote attacker to exhaust device memory, resulting in a DoS condition that would require a manual reboot. (CVE-2026-20106)
• A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. (CVE-2026-20039)
• A vulnerability in the handling of the embryonic connection limits in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause incoming TCP SYN packets to be dropped incorrectly. (CVE-2026-20082)
• A vulnerability in the web-based management interface of Cisco Secure FMC Software could allow an authenticated, remote attacker to conduct SQL injection attacks on an affected system. (CVE-2026-20002)
• A vulnerability in the REST API of Cisco Secure FMC Software could allow an authenticated, remote attacker to conduct SQL injection attacks on an affected system. (CVE-2026-20001, CVE-2026-20003)
• A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an authenticated, remote attacker with valid VPN user credentials to cause a DoS condition on an affected device that may also impact the availability of services to devices elsewhere in the network. (CVE-2026-20014)
• A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device that may also impact the availability of services to devices elsewhere in the network. (CVE-2026-20013)
• A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device that may impact the availability of services to devices elsewhere in the network. (CVE-2026-20015)
• A vulnerability in the processing of Galois/Counter Mode (GCM)-encrypted Internet Key Exchange version 2 (IKEv2) IPsec traffic of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. (CVE-2026-20049)
• A vulnerability in the CLI of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software in multiple context mode could allow an authenticated, local attacker with administrative privileges in one context to copy files to or from another context, including configuration files. (CVE-2026-20062)
• Multiple vulnerabilities in the OSPF feature of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an adjacent attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. (CVE-2026-20020, CVE-2026-20021, CVE-2026-20022, CVE-2026-20023, CVE-2026-20024, CVE-2026-20025)
• A vulnerability in the Do Not Decrypt exclusion feature of the SSL decryption feature of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. (CVE-2026-20050)
• Multiple vulnerabilities in the CLI feature of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, local attacker to cause a device to execute commands with elevated privileges or reload unexpectedly, resulting in a denial of service (DoS) condition. (CVE-2026-20016, CVE-2026-20017, CVE-2026-20063, CVE-2026-20064)
• A vulnerability in the SAML 2.0 single sign-on (SSO) feature of Cisco Secure Firewall 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 the SAML feature and access sensitive, browser-based information. (CVE-2026-20102)
• 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. (CVE-2026-20070)
• A vulnerability in a small subset of CLI commands that are used on Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, local attacker to craft Lua code that could be used on the underlying operating system as root. (CVE-2026-20008)
• A vulnerability in the lockdown mechanism of Cisco Secure Firewall Management Center (FMC) Software could allow an authenticated, local attacker to perform arbitrary commands as root. (CVE-2026-20044)
• A vulnerability in the sftunnel functionality of Cisco Secure Firewall Management Center (FMC) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with administrative privileges to write arbitrary files as root on the underlying operating system. (CVE-2026-20018)
• A vulnerability in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to send traffic that should be denied through an affected device. (CVE-2026-20073)
• A vulnerability in the memory management handling for the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart. (CVE-2026-20052)
• A vulnerability in the Snort 2 and Snort 3 deep packet inspection of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured Snort rules and allow traffic onto the network that should have been dropped. (CVE-2026-20007)
• A vulnerability in the TLS cryptography functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to unexpectedly restart, resulting in a denial of service (DoS) condition. (CVE-2026-20006)
• Multiple Cisco products are affected by vulnerabilities in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. (CVE-2026-20005, CVE-2026-20065, CVE-2026-20066, CVE-2026-20067, CVE-2026-20068)
• Multiple Cisco products are affected by vulnerabilities in the Snort 3 Visual Basic for Applications (VBA) Decompression Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to unexpectedly restart, resulting in a denial of service (DoS) condition. (CVE-2026-20053, CVE-2026-20054, CVE-2026-20057, CVE-2026-20058)
• A vulnerability in the implementation of the proprietary SSH stack with SSH key-based authentication in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to log in to a Cisco Secure Firewall ASA device and execute commands as a specific user. (CVE-2026-20009)
• 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. (CVE-2026-20069)

Successful exploitation of the most severe of these vulnerabilities could allow for remote code execution as root, which may lead to the complete compromise of the affected device.

We recommend the following actions be taken:

• Apply appropriate updates provided by Cisco to vulnerable systems immediately after appropriate testing. (M1051: Update Software)
• Safeguard 7.1 : Establish and Maintain a Vulnerability Management Process: Establish and maintain a documented vulnerability management process for enterprise assets. Review and update documentation annually, or when significant enterprise changes occur that could impact this Safeguard.
• Safeguard 7.2 : Establish and Maintain a Remediation Process: Establish and maintain a risk-based remediation strategy documented in a remediation process, with monthly, or more frequent, reviews.
• Safeguard 7.4: Perform Automated Application Patch Management: Perform application updates on enterprise assets through automated patch management on a monthly, or more frequent, basis.
• Safeguard 7.6 : Perform Automated Vulnerability Scans of Externally-Exposed Enterprise Assets: Perform automated vulnerability scans of externally-exposed enterprise assets using a SCAP-compliant vulnerability scanning tool. Perform scans on a monthly, or more frequent, basis.
• Safeguard 7.7 : Remediate Detected Vulnerabilities: Remediate detected vulnerabilities in software through processes and tooling on a monthly, or more frequent, basis, based on the remediation process.
• Safeguard 16.13 Conduct Application Penetration Testing: Conduct application penetration testing. For critical applications, authenticated penetration testing is better suited to finding business logic vulnerabilities than code scanning and automated security testing. Penetration testing relies on the skill of the tester to manually manipulate an application as an authenticated and unauthenticated user.
• Safeguard 12.1: Ensure Network Infrastructure is Up-to-Date: Ensure network infrastructure is kept up-to-date. Example implementations include running the latest stable release of software and/or using currently supported network-as-a-service (NaaS) offerings. Review software versions monthly, or more frequently, to verify software support.
• Safeguard 18.1 : Establish and Maintain a Penetration Testing Program: Establish and maintain a penetration testing program appropriate to the size, complexity, and maturity of the enterprise. Penetration testing program characteristics include scope, such as network, web application, Application Programming Interface (API), hosted services, and physical premise controls; frequency; limitations, such as acceptable hours, and excluded attack types; point of contact information; remediation, such as how findings will be routed internally; and retrospective requirements.
• Safeguard 18.2 : Perform Periodic External Penetration Tests: Perform periodic external penetration tests based on program requirements, no less than annually. External penetration testing must include enterprise and environmental reconnaissance to detect exploitable information. Penetration testing requires specialized skills and experience and must be conducted through a qualified party. The testing may be clear box or opaque box.
• Safeguard 18.3 : Remediate Penetration Test Findings: Remediate penetration test findings based on the enterprise’s policy for remediation scope and prioritization.
• Apply the Principle of Least Privilege to all systems and services. Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack. (M1026: Privileged Account Management)
• Safeguard 4.7: Manage Default Accounts on Enterprise Assets and Software: Manage default accounts on enterprise assets and software, such as root, administrator, and other pre-configured vendor accounts. Example implementations can include: disabling default accounts or making them unusable.
• Safeguard 5.4: Restrict Administrator Privileges to Dedicated Administrator Accounts: Restrict administrator privileges to dedicated administrator accounts on enterprise assets. Conduct general computing activities, such as internet browsing, email, and productivity suite use, from the user’s primary, non-privileged account.
• Vulnerability scanning is used to find potentially exploitable software vulnerabilities to remediate them. (M1016: Vulnerability Scanning)
• Safeguard 16.13: Conduct Application Penetration Testing: Conduct application penetration testing. For critical applications, authenticated penetration testing is better suited to finding business logic vulnerabilities than code scanning and automated security testing. Penetration testing relies on the skill of the tester to manually manipulate an application as an authenticated and unauthenticated user.
• Use capabilities to detect and block conditions that may lead to or be indicative of a software exploit occurring. (M1050: Exploit Protection)
• Safeguard 10.5: Enable Anti-Exploitation Features: Enable anti-exploitation features on enterprise assets and software, where possible, such as Microsoft? Data Execution Prevention (DEP), Windows? Defender Exploit Guard (WDEG), or Apple? System Integrity Protection (SIP) and Gatekeeper™.
• Architect sections of the network to isolate critical systems, functions, or resources. Use physical and logical segmentation to prevent access to potentially sensitive systems and information. Use a DMZ to contain any internet-facing services that should not be exposed from the internal network. Configure separate virtual private cloud (VPC) instances to isolate critical cloud systems. (M1030: Network Segmentation)
• Safeguard 12.2: Establish and Maintain a Secure Network Architecture: Establish and maintain a secure network architecture. A secure network architecture must address segmentation, least privilege, and availability, at a minimum.
• Use capabilities to detect and block conditions that may lead to or be indicative of a software exploit occurring. (M1050: Exploit Protection)
• Safeguard 10.5: Enable Anti-Exploitation Features: Enable anti-exploitation features on enterprise assets and software, where possible, such as Microsoft? Data Execution Prevention (DEP), Windows? Defender Exploit Guard (WDEG), or Apple? System Integrity Protection (SIP) and Gatekeeper™.