CVE-2026-20262: Cisco Catalyst SD-WAN Manager Directory or Path Traversal Vulnerability

Cisco Catalyst SD-WAN Manager contains a directory or path traversal vulnerability that permits an authenticated remote attacker to create or overwrite arbitrary files on the affected system. The flaw is tracked as CVE-2026-20262 and is classified under CWE-22. Because the product manages wide-area network infrastructure, successful abuse can alter configuration, binaries, or logs that control traffic routing and device behavior.

How it works

CWE-22 path traversal occurs when user-supplied input is used to construct filesystem paths without sufficient validation or canonicalization. An attacker who already possesses valid credentials can supply sequences such as dot-dot-slash or absolute paths that cause the application to reference locations outside the intended directory. The result is the ability to create new files or replace existing ones anywhere on the filesystem that the process can reach.

The vulnerability does not require unauthenticated network access; the attacker must first authenticate to the SD-WAN Manager interface. No further exploit mechanics are documented in the available summary.

Am I affected? How to find it in your systems

Inventory all deployments of Cisco Catalyst SD-WAN Manager. This software typically runs as a centralized management plane for SD-WAN fabrics and may be deployed on-premises or in cloud-hosted instances. Examine configuration management databases, asset inventories, and network diagrams for instances that expose the management interface.

• Confirm the exact software version and any applied patches against the vendor advisory, as the summary does not list specific releases.
• Review authentication logs and API access records for unexpected administrative sessions that could indicate attempts to reach the vulnerable code path.
• Check filesystem integrity monitoring or change-detection tools for unexpected file creation or modification timestamps on the management host.

How to remediate

Apply the vendor-supplied update referenced in the official advisory. After patching, verify that the management plane is running the corrected code and that prior credentials have been rotated.

• Restrict network access to the SD-WAN Manager interface to only the minimal set of administrative source addresses.
• Enforce strong, unique credentials and multi-factor authentication for all management accounts.
• Enable filesystem monitoring on directories that store configuration and executable content so that unexpected writes generate alerts.

If you can't patch immediately

Follow the mitigations prescribed by the vendor and ensure compliance with CISA BOD 26-04 guidance on prioritizing security updates. Segment the SD-WAN Manager host so that it is reachable only from trusted management networks. Where technically feasible, disable or tightly control any features that accept user-controlled path input until the update can be applied. Increase logging verbosity on authentication and file-write events and forward those logs to a central collector for review. If compensating controls cannot be implemented, evaluate whether continued use of the product meets organizational risk tolerance and regulatory requirements.

If your data may have been exposed

Actively exploited vulnerabilities of this class can lead to unauthorized changes that facilitate further compromise. Organizations can run a free exposure scan of their email addresses to check against known breach data.