CVE-2026-20303 CRITICAL

CVE-2026-20303: Cisco Catalyst SD-WAN Security Hardening Release - Input Validation Vulnerabilities

Vendor Cisco
Product Cisco Catalyst SD-WAN Controller
Weakness CWE-20 · Input validation
Published August 5, 2026
Last update August 5, 2026
View on NVD All CVEs

CVSS base score

9.9/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

August 5, 2026 CVE published
August 5, 2026 Record updated

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