The Cisco SD-WAN situation this week is worth a close look if it's in your environment. CVE-2026-20127 is a CVSS 10 auth bypass that was a zero-day at time of exploitation — and CISA/Five Eyes confirmed it's been in active use since at least 2023. That means potentially years of silent access before ED-26-03 dropped.
A few things that stood out doing the writeup:
No workaround exists. Upgrade is the only path. The attack chain chains to CVE-2022-20775 for root — both need the same patch bundle Threat actors insert rogue devices that look like legitimate SD-WAN components and actively remove forensic artifacts — compromise assessment needs to happen in parallel with patching, not after Logs stored locally on the device are attacker-controllable — external syslog should have been on already
Covered the full remediation steps, hardening actions, and dropped ready-to-use POAM language for anyone who needs to open a POAM under BOD 22-01.
Link in comments.
Multiple vulnerabilities in the CLI of Cisco SD-WAN Software could allow an authenticated, local attacker to gain elevated privileges. These vulnerabilities are due to improper access controls on commands within the application CLI. An attacker could exploit these vulnerabilities by running a malicious command on the application CLI. A successful exploit could allow the attacker to execute arbitrary commands as the root user.
A vulnerability in the CLI of Cisco SD-WAN Software could allow an authenticated, local attacker to gain elevated privileges. This vulnerability is due to improper access controls on commands within the application CLI. An attacker could exploit this vulnerability by running a maliciously crafted command on the application CLI. A successful exploit could allow the attacker to execute arbitrary commands as the root user. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sd-wan-priv-E6e8tEdF
Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute denial of service (DoS) attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.
A vulnerability in the CLI of Cisco SD-WAN Software could allow an authenticated, local attacker to access sensitive information on an affected device. The vulnerability is due to insufficient input validation of requests that are sent to the iperf tool. An attacker could exploit this vulnerability by sending a crafted request to the iperf tool, which is included in Cisco SD-WAN Software. A successful exploit could allow the attacker to obtain any file from the filesystem of an affected device.
Multiple vulnerabilities in the web-based management interface of Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to bypass authorization and modify the configuration of an affected system, gain access to sensitive information, and view information that they are not authorized to access. For more information about these vulnerabilities, see the Details section of this advisory.
Multiple vulnerabilities in Cisco SD-WAN products could allow an authenticated attacker to perform command injection attacks against an affected device, which could allow the attacker to take certain actions with root privileges on the device. For more information about these vulnerabilities, see the Details section of this advisory.
Multiple vulnerabilities in Cisco SD-WAN products could allow an authenticated attacker to perform command injection attacks against an affected device, which could allow the attacker to take certain actions with root privileges on the device. For more information about these vulnerabilities, see the Details section of this advisory.
Multiple vulnerabilities in Cisco SD-WAN products could allow an authenticated attacker to perform command injection attacks against an affected device, which could allow the attacker to take certain actions with root privileges on the device. For more information about these vulnerabilities, see the Details section of this advisory.
Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute denial of service (DoS) attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.
Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute denial of service (DoS) attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.
Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute denial of service (DoS) attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.
Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute denial of service (DoS) attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.
Multiple vulnerabilities in Cisco SD-WAN products could allow an authenticated attacker to perform command injection attacks against an affected device, which could allow the attacker to take certain actions with root privileges on the device. For more information about these vulnerabilities, see the Details section of this advisory.
Multiple vulnerabilities in Cisco SD-WAN products could allow an authenticated attacker to perform command injection attacks against an affected device, which could allow the attacker to take certain actions with root privileges on the device. For more information about these vulnerabilities, see the Details section of this advisory.
Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.
Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.
A vulnerability in Cisco SD-WAN Solution Software could allow an unauthenticated, remote attacker to cause a buffer overflow on an affected device. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending crafted traffic to an affected device. A successful exploit could allow the attacker to gain access to information that they are not authorized to access, make changes to the system that they are not authorized to make, and execute commands on an affected system with privileges of the root user. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdbufof-h5f5VSeL
A vulnerability in the web-based management interface of Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to conduct SQL injection attacks on an affected system. The vulnerability exists because the web-based management interface improperly validates values within SQL queries. An attacker could exploit this vulnerability by authenticating to the application and sending malicious SQL queries to an affected system. A successful exploit could allow the attacker to modify values on or return values from the underlying database or the operating system.
A vulnerability in the web-based management interface of Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to read arbitrary files on the underlying filesystem of the device. The vulnerability is due to insufficient file scope limiting. An attacker could exploit this vulnerability by creating a specific file reference on the filesystem and then accessing it through the web-based management interface. A successful exploit could allow the attacker to read arbitrary files from the filesystem of the underlying operating system.
A vulnerability in the web-based management interface of the Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface. The vulnerability exists because the web-based management interface does not properly validate user-supplied input. An attacker could exploit this vulnerability by persuading a user to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the interface or access sensitive, browser-based information.
A vulnerability in the web-based management interface of Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to conduct path traversal attacks and obtain read access to sensitive files on an affected system. The vulnerability is due to insufficient validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request that contains directory traversal character sequences to the affected system. A successful exploit could allow the attacker to view arbitrary files on the affected system.
A vulnerability in the web UI of Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to gain read and write access to information that is stored on an affected system. The vulnerability is due to improper handling of XML External Entity (XXE) entries when parsing certain XML files. An attacker could exploit this vulnerability by persuading a user to import a crafted XML file with malicious entries. A successful exploit could allow the attacker to read and write files within the affected application.
A vulnerability in the CLI of Cisco SD-WAN vManage Software could allow an authenticated, local attacker to inject arbitrary commands that are executed with root privileges. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by authenticating to the device and submitting crafted input to the CLI. The attacker must be authenticated to access the CLI. A successful exploit could allow the attacker to execute commands with root privileges.
A vulnerability in Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to execute code with root privileges on an affected system. The vulnerability is due to insufficient input sanitization during user authentication processing. An attacker could exploit this vulnerability by sending a crafted response to the Cisco SD-WAN vManage Software. A successful exploit could allow the attacker to access the software and execute commands they should not be authorized to execute.
A vulnerability in the deep packet inspection (DPI) engine of Cisco SD-WAN vEdge Routers could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected system. The vulnerability is due to insufficient handling of malformed packets. An attacker could exploit this vulnerability by sending crafted packets through an affected device. A successful exploit could allow the attacker to cause the device to reboot, resulting in a DoS condition.
A vulnerability in the web management interface of Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to conduct directory traversal attacks and obtain read and write access to sensitive files on a targeted system. The vulnerability is due to a lack of proper validation of files that are uploaded to an affected device. An attacker could exploit this vulnerability by uploading a crafted file to an affected system. An exploit could allow the attacker to view or modify arbitrary files on the targeted system.
A vulnerability in Cisco SD-WAN Solution Software could allow an authenticated, local attacker to elevate privileges to Administrator on the underlying operating system. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending a crafted request to an affected system. A successful exploit could allow the attacker to gain administrative privileges.
A vulnerability in the web-based management interface for Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to impact the integrity of an affected system by executing arbitrary SQL queries. The vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending crafted input that includes SQL statements to an affected system. A successful exploit could allow the attacker to modify entries in some database tables, affecting the integrity of the data.
A vulnerability in the web-based management interface of Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to consume excessive system memory and cause a denial of service (DoS) condition on an affected system. The vulnerability is due to inefficient memory management. An attacker could exploit this vulnerability by sending a large number of crafted HTTP requests to the affected web-based management interface. A successful exploit could allow the attacker to exhaust system memory, which could cause the system to stop processing new connections and could result in a DoS condition.