CVE-2026-20303
Received Received - Intake

Improper Input Validation in Cisco Catalyst SD-WAN

Publication date: 2026-08-05

Last updated on: 2026-08-05

Assigner: Cisco Systems, Inc.

Description
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Catalyst SD-WAN engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20303 are related to improper input validation issues that are grouped under the Common Weakness Enumeration (CWE) CWE-20.

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Meta Information

Published
2026-08-05
Last Modified
2026-08-05
Generated
2026-08-05
AI Q&A
2026-08-05
EPSS Evaluated
N/A
NVD
CVE-2026-20303
EUVD
EUVD-2026-53469

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
cisco catalyst_sd-wan *
cisco catalyst_sd-wan_software *

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-20 The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

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Executive Summary

CVE-2026-20303 is a vulnerability in Cisco Catalyst SD-WAN Software caused by improper input validation, specifically related to CWE-20. This can include issues like path traversal or external path control, allowing unauthorized access or manipulation of system files.

Detection Guidance

Detection requires checking the Cisco Catalyst SD-WAN Software version against the fixed releases listed in Cisco's advisory. Use commands like 'show version' on the device to verify the software version. Compare it with the recommended versions provided in the advisory.

Impact Analysis

This vulnerability could allow an attacker to execute arbitrary code, gain elevated privileges, or access sensitive data on affected systems. It impacts all deployment types of Cisco Catalyst SD-WAN Software, including on-premises, cloud-based, and government deployments.

Compliance Impact

This vulnerability, due to improper input validation (CWE-20), could allow unauthorized access or data manipulation, potentially violating confidentiality and integrity requirements in standards like GDPR and HIPAA. Unpatched systems may fail compliance checks for data protection controls.

Mitigation Strategies

Immediately upgrade to the fixed software releases provided by Cisco in their advisory. Since no workarounds exist, updating is the only mitigation. Ensure backups are taken before upgrading and test the update in a non-production environment first.

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