CVE-2026-20127

Google Threat Intelligence · Jun 24, 2026

Written by: Chester Sng, Pete Boonyakarn, Logeswaran Nadarajan Introduction  In early 2026, Mandiant identified a threat actor targeting SD-WAN infrastructure at a service provider. After gaining initial access, the threat actor exploited a zero-day vulnerability (CVE-2026-20245) in Cisco Catalyst SD-WAN to escalate privileges from a compromised administrative account to root-level access. The vulnerability stems from the device’s file upload feature lacking the ability to properly filter malicious data. Throughout the intrusion, to maintain operational security and avoid detection, the threat actor consistently employed anti-forensic techniques, selectively deleting and restoring system configuration files that were modified during their activities. Key Observations Rogue Peering and Credential Manipulation: In March 2026, a threat actor established initial access via unauthorized peering connections to facilitate Secure Shell (SSH) access. The threat actor used that access to manipulate default account passwords to evade detection. Exploitation of CVE-2026-20245: Subsequently, the attacker leveraged a zero-day privilege escalation vulnerability (now tracked as CVE-2026-20245) in Cisco Catalyst SD-WAN Manager to gain root-level access via a malicious CSV upload. Extensive Anti-Forensic Cleanup: The threat actor deleted malicious files, reverted configuration changes, and executed a validation script to ensure indicators are purged. What is SD-WAN? Traditional Wide Area Networks (WANs) rely heavily on physical, proprietary hardware routers to direct traffic. This model is often rigid, complex to scale, and struggles to handle the demands of modern cloud computing. Software-Defined Wide Area Network (SD-WAN) solves this by decoupling the network’s management and control logic from the underlying physical hardware. Instead of configuring individual routers one by one, a centralized software controller is used to orchestrate the entire network from a single...

Google Threat Intelligence · Jun 24, 2026

Written by: Chester Sng, Pete Boonyakarn, Logeswaran Nadarajan, Lukasz Lamparski Introduction  In early 2026, Mandiant identified a threat actor targeting SD-WAN infrastructure at a service provider. After gaining initial access, the threat actor exploited a zero-day vulnerability (CVE-2026-20245) in Cisco Catalyst SD-WAN to escalate privileges from a compromised administrative account to root-level access. The vulnerability stems from the device’s file upload feature lacking the ability to properly filter malicious data. Throughout the intrusion, to maintain operational security and avoid detection, the threat actor consistently employed anti-forensic techniques, selectively deleting and restoring system configuration files that were modified during their activities. Key Observations Rogue Peering and Credential Manipulation: In March 2026, a threat actor established initial access via unauthorized peering connections to facilitate Secure Shell (SSH) access. The threat actor used that access to manipulate default account passwords to evade detection. Exploitation of CVE-2026-20245: Subsequently, the attacker leveraged a zero-day privilege escalation vulnerability (now tracked as CVE-2026-20245) in Cisco Catalyst SD-WAN Manager to gain root-level access via a malicious CSV upload. Extensive Anti-Forensic Cleanup: The threat actor deleted malicious files, reverted configuration changes, and executed a validation script to ensure indicators are purged. What is SD-WAN? Traditional Wide Area Networks (WANs) rely heavily on physical, proprietary hardware routers to direct traffic. This model is often rigid, complex to scale, and struggles to handle the demands of modern cloud computing. Software-Defined Wide Area Network (SD-WAN) solves this by decoupling the network’s management and control logic from the underlying physical hardware. Instead of configuring individual routers one by one, a centralized software controller is used to orchestrate the entire...

Cisco Security Advisory · Jun 16, 2026

A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, and Cisco Catalyst SD-WAN Validator, formerly SD-WAN vBond, could allow an unauthenticated, remote attacker to bypass authentication and obtain administrative privileges on an affected system. This vulnerability exists because the peering authentication mechanism in an affected system is not working properly. An attacker could exploit this vulnerability by sending crafted requests to an affected system. A successful exploit could allow the attacker to log in to an affected Cisco Catalyst SD-WAN Controller as an internal, high-privileged, non-root user account. Using this account, the attacker could access NETCONF, which would then allow the attacker to manipulate network configuration for the SD-WAN fabric.  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-sdwan-rpa-EHchtZk Security Impact Rating: Critical CVE: CVE-2026-20127

Cisco Security Advisory · Jun 09, 2026

A vulnerability in the CLI of Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, and Cisco Catalyst SD-WAN Validator, formerly SD-WAN vBond, could allow an authenticated, local attacker to execute arbitrary commands as root by supplying a crafted file to the affected system. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by uploading a crafted file to the affected system. A successful exploit could allow the attacker to perform command injection attacks on an affected system and elevate their privileges as the root user.  To exploit this vulnerability, the attacker must have netadmin privileges on the affected system. This would require valid credentials or exploitation of CVE-2026-20182 or CVE-2026-20127. Cisco is not aware of successful exploitation by other methods. Cisco has observed limited cases where the exploitation of this bug resulted in a configuration change pushed to edge devices. Cisco recommends that customers upgrade to the fixed software that is documented in the Catalyst SD-WAN Security Advisory that was published on May 14, 2026, and verify the configuration of the edge devices. Cisco has released software updates that address this vulnerability. This advisory will be updated as more information becomes available. There are no workarounds that address this vulnerability. Important: To preserve possible indicators of compromise, customers should issue the request admin-tech command from each of the control components in the SD-WAN deployment before upgrading. After the admin-tech file has been collected, software should be upgraded at the earliest opportunity. Before upgrading an SD-WAN deployment to a fixed release, retain relevant logs. After upgrading, verify that the system has not been compromised by checking the logs for the indicators of compromise as documented in this advisory. If the logs show...

Cisco Security Advisory · Jun 04, 2026

A vulnerability in the CLI of Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, could allow an authenticated, local attacker to execute arbitrary commands as root by supplying a crafted file to the affected system. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by uploading a crafted file to the affected system. A successful exploit could allow the attacker to perform command injection attacks on an affected system and elevate their privileges as the root user.  To exploit this vulnerability, the attacker must have netadmin privileges on the affected system. This would require valid credentials or exploitation of CVE-2026-20182 or CVE-2026-20127. Cisco is not aware of successful exploitation by other methods. Cisco has observed limited cases where the exploitation of this bug resulted in a configuration change pushed to edge devices. Cisco recommends that customers upgrade to the fixed software that is documented in the Catalyst SD-WAN Security Advisory that was published on May 14, 2026, and verify the configuration of the edge devices. Cisco has not released software updates that address this vulnerability. There are no workarounds that address this vulnerability. Important: To preserve possible indicators of compromise, customers should issue the request admin-tech command from each of the control components in the SD-WAN deployment before upgrading. After the admin-tech file has been collected, software should be upgraded at the earliest opportunity. Before upgrading an SD-WAN deployment to a fixed release, retain relevant logs. After upgrading, verify that the system has not been compromised by checking the logs for the indicators of compromise as documented in this advisory. If the logs show indicators of compromise and the system is confirmed to be compromised, applying the software update alone will not resolve the vulnerability. In such cases, follow the specific...

github · Created 2026-07-12 04:08:28 UTC · 0 stars

github · Created 2026-06-14 13:15:00 UTC · 0 stars

CVE-2026-20127

github · Created 2026-03-09 14:38:24 UTC · 23 stars

An exploit for the Cisco Catalyst SD-WAN Controller authentication bypass vulnerability, CVE-2026-20127

github · Created 2026-03-08 09:04:34 UTC · 0 stars

Cisco SD-WAN Exposure & Potential Vulnerability Scanner (Passive Fingerprinting) 2026

github · Created 2026-03-07 09:39:29 UTC · 2 stars

github · Created 2026-03-05 15:28:31 UTC · 4 stars

Cisco Catalyst SD-WAN 身份验证绕过漏洞(CVE-2026-20127)利用EXP

github · Created 2026-03-04 03:25:57 UTC · 0 stars

Walkthrough of the CVSS 10.0 authentication bypass in Cisco Catalyst SD-WAN from first malformed peering request to root on the management plane.

github · Created 2026-03-04 01:20:17 UTC · 31 stars