Vulnerability Monitor

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CVE-2026-20127


A vulnerability in the peering authentication in Cisco Catalyst SD-WAN Controller, formerly SD-WAN vSmart, and Cisco Catalyst SD-WAN Manager, formerly SD-WAN vManage, 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. 


Security Impact Summary

This vulnerability carries a CRITICAL severity rating with a CVSS v3.1 score of 10.0, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 2 products from cisco, from cisco organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2026, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2026-02-25T17:25:29.477

Last Modified

2026-02-26T16:20:02.187

Status

Analyzed

Source

[email protected]

Severity

CVSSv3.1: 10.0 (CRITICAL)

Weaknesses
  • Type: Secondary
    CWE-287
  • Type: Primary
    CWE-287

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application cisco catalyst_sd-wan_manager < 20.9.8.2 Yes
Application cisco catalyst_sd-wan_manager < 20.12.5.3 Yes
Application cisco catalyst_sd-wan_manager < 20.15.4.2 Yes
Application cisco catalyst_sd-wan_manager < 20.18.2.1 Yes
Application cisco catalyst_sd-wan_manager 20.12.6 Yes
Application cisco sd-wan_vsmart_controller < 20.9.8.2 Yes
Application cisco sd-wan_vsmart_controller < 20.12.5.3 Yes
Application cisco sd-wan_vsmart_controller < 20.15.4.2 Yes
Application cisco sd-wan_vsmart_controller < 20.18.2.1 Yes
Application cisco sd-wan_vsmart_controller 20.12.6 Yes

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For cisco's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.