CVE-2026-20294: Cisco SD-WAN Manager Info Disclosure Flaw

CVE-2026-20294 Overview

CVE-2026-20294 is an information disclosure vulnerability in the web-based management interface of Cisco Catalyst SD-WAN Manager. An authenticated, remote attacker with low privileges can view sensitive information in clear text on an affected system. The flaw is tracked under CWE-319: Cleartext Transmission of Sensitive Information.

The vulnerability stems from insufficient access control enforcement for specific template types not included in the encryption allowlist. Attackers can retrieve authentication credentials by reading logs on the local system or on a remote logging server. Exposure of these credentials can enable further compromise of network infrastructure and connected services.

Critical Impact
A low-privileged authenticated user can obtain clear-text authentication credentials from log data, enabling lateral movement across SD-WAN-managed network infrastructure.

Affected Products

Cisco Catalyst SD-WAN Manager (web-based management interface)
SD-WAN template configurations not covered by the encryption allowlist
Remote logging servers receiving SD-WAN Manager log output

Discovery Timeline

2026-08-05 - CVE-2026-20294 published to NVD
2026-08-05 - Last updated in NVD database

Technical Details for CVE-2026-20294

Vulnerability Analysis

Cisco Catalyst SD-WAN Manager maintains an encryption allowlist that specifies which template types trigger credential encryption during processing and logging. Template types omitted from this allowlist are handled without encryption enforcement. Sensitive fields inside those templates are written in clear text to system logs.

An authenticated attacker with low privileges can access these logs through the web-based management interface. The same clear-text data is forwarded to any configured remote syslog destination. Credentials exposed through this path can include device authentication material used across the SD-WAN fabric.

Root Cause

The root cause is incomplete access control coupled with an incomplete encryption allowlist. Template types outside the allowlist bypass the credential-masking routine before being written to log storage. The design assumes only privileged operators can read logs, but the interface exposes them to low-privileged roles as well.

Attack Vector

Exploitation requires network access to the SD-WAN Manager interface and valid low-privileged credentials. The attacker authenticates, navigates to log views, and reads credential material embedded in affected template log entries. No user interaction and no additional privilege escalation is required to view the exposed data.

The vulnerability manifests during template processing and log emission. See the Cisco Security Advisory for the vendor description and remediation details.

Detection Methods for CVE-2026-20294

Indicators of Compromise

Log entries on SD-WAN Manager or remote syslog servers containing clear-text credentials, keys, or authentication tokens tied to specific template types.
Access to log viewing endpoints in the SD-WAN Manager web interface by low-privileged user accounts.
Unexpected authentication events on downstream network devices using credentials that appear in SD-WAN Manager logs.

Detection Strategies

Audit SD-WAN Manager audit logs for read operations against log or template views performed by non-administrative roles.
Scan local and remote syslog stores for regex patterns matching credential formats (passwords, community strings, pre-shared keys).
Correlate credential-bearing log lines with subsequent authentication attempts on managed edge routers.

Monitoring Recommendations

Forward SD-WAN Manager logs to a centralized analytics platform and alert on template-related events containing credential-like strings.
Track user role assignments and any elevation or role changes within SD-WAN Manager.
Monitor remote syslog server access controls to prevent unauthorized retrieval of exported log data.

How to Mitigate CVE-2026-20294

Immediate Actions Required

Apply the fixed software release identified in the Cisco Security Advisory.
Rotate any credentials that were configured through affected template types, including device passwords, SNMP community strings, and pre-shared keys.
Restrict SD-WAN Manager log access to administrative roles until patching is complete.

Patch Information

Cisco has published fixed software versions in the vendor advisory. Refer to the Cisco Security Advisory for the specific fixed releases applicable to your Catalyst SD-WAN Manager deployment. No official workarounds are listed by the vendor at time of publication.

Workarounds

Limit user accounts with log or template read permissions to trusted administrators only.
Segregate remote syslog infrastructure and enforce strict access controls on stored log data.
Review template configurations and remove sensitive fields from unaffected template types where feasible until the patch is deployed.

bash

# Configuration example
# Review users with log/template read privileges in SD-WAN Manager and
# restrict access until the patched release is installed.
# Consult the Cisco advisory for authoritative remediation steps.