As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20272 are related to issues with improper neutralization of special elements that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-74.

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20267 are related to improper access control issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-284.

A vulnerability in the Authentication, Authorization, and Accounting (AAA) feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker to bypass command authorization and copy files to or from the file system of an affected device using the Secure Copy Protocol (SCP). This vulnerability is due to incorrect processing of SCP commands in AAA command authorization checks. An attacker with valid credentials and level 15 privileges could exploit this vulnerability by using SCP to connect to an affected device from an external machine. A successful exploit could allow the attacker to obtain or change the configuration of the affected device and put files on or retrieve files from the affected device.

A vulnerability in the web UI of Cisco IOS XE Software could allow an authenticated, remote attacker to execute arbitrary commands with root privileges on the underlying operating system of an affected device. The vulnerability is due to improper input sanitization. An attacker could exploit this vulnerability by uploading a crafted file to the web UI of an affected device. A successful exploit could allow the attacker to inject and execute arbitrary commands with root privileges on the device.

A vulnerability in the web UI of Cisco IOS XE Software could allow an authenticated, remote attacker with administrative privileges to execute arbitrary code with root privileges on the underlying Linux shell. The vulnerability is due to improper validation of user-supplied input. An attacker could exploit this vulnerability by first creating a malicious file on the affected device itself and then uploading a second malicious file to the device. A successful exploit could allow the attacker to execute arbitrary code with root privileges or bypass licensing requirements on the device.

A vulnerability in the web UI of Cisco IOS XE Software could allow an authenticated, remote attacker to inject and execute arbitrary commands with administrative privileges on the underlying operating system of an affected device. The vulnerability is due to insufficient validation of user-supplied input to the web UI. An attacker could exploit this vulnerability by submitting crafted input to the web UI. A successful exploit could allow an attacker to execute arbitrary commands with administrative privileges on an affected device.

A vulnerability in the web-based user interface (web UI) of Cisco IOS XE Software could allow an authenticated, remote attacker with read-only privileges to inject IOS commands to an affected device. The injected commands should require a higher privilege level in order to be executed. The vulnerability is due to insufficient input validation of specific HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a specific web UI endpoint on an affected device. A successful exploit could allow the attacker to inject IOS commands to the affected device, which could allow the attacker to alter the configuration of the device or cause a denial of service (DoS) condition.

A vulnerability in Role Based Access Control (RBAC) functionality of Cisco IOS XE Web Management Software could allow a Read-Only authenticated, remote attacker to execute commands or configuration changes as an Admin user. The vulnerability is due to incorrect handling of RBAC for the administration GUI. An attacker could exploit this vulnerability by sending a modified HTTP request to the affected device. An exploit could allow the attacker as a Read-Only user to execute CLI commands or configuration changes as if they were an Admin user.

A vulnerability in the vDaemon process in Cisco IOS XE SD-WAN Software could allow an unauthenticated, remote attacker to cause a buffer overflow on an affected device. This vulnerability is due to insufficient bounds checking when the device processes traffic. An attacker could exploit this vulnerability by sending crafted traffic to the device. The attacker must have a man-in-the-middle position between Cisco vManage and an associated device that is running an affected version of Cisco IOS XE SD-WAN Software. An exploit could allow the attacker to conduct a controllable buffer overflow attack (and possibly execute arbitrary commands as the root user) or cause a device reload, resulting in a denial of service (DoS) condition.

A vulnerability in the authentication, authorization, and accounting (AAA) function of Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass NETCONF or RESTCONF authentication and do either of the following: Install, manipulate, or delete the configuration of an affected device Cause memory corruption that results in a denial of service (DoS) on an affected device This vulnerability is due to an uninitialized variable. An attacker could exploit this vulnerability by sending a series of NETCONF or RESTCONF requests to an affected device. A successful exploit could allow the attacker to use NETCONF or RESTCONF to install, manipulate, or delete the configuration of a network device or to corrupt memory on the device, resulting a DoS.

A vulnerability in the web UI feature of Cisco IOS XE Software could allow an authenticated, remote attacker to perform an injection attack against an affected device. This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending crafted input to the web UI API. A successful exploit could allow the attacker to inject commands to the underlying operating system with root privileges.

A vulnerability in the Central Web Authentication (CWA) feature of Cisco IOS XE Software for Wireless Controllers could allow an unauthenticated, adjacent attacker to bypass the pre-authentication access control list (ACL), which could allow access to network resources before user authentication. This vulnerability is due to a logic error when activating the pre-authentication ACL that is received from the authentication, authorization, and accounting (AAA) server. An attacker could exploit this vulnerability by connecting to a wireless network that is configured for CWA and sending traffic through an affected device that should be denied by the configured ACL before user authentication. A successful exploit could allow the attacker to bypass configured ACL protections on the affected device before the user authentication is completed, allowing the attacker to access trusted networks that the device might be protecting.

Multiple vulnerabilities in the Cisco IOx application hosting environment on multiple Cisco platforms could allow an attacker to inject arbitrary commands into the underlying host operating system, execute arbitrary code on the underlying host operating system, install applications without being authenticated, or conduct a cross-site scripting (XSS) attack against a user of the affected software. For more information about these vulnerabilities, see the Details section of this advisory.