Monitor vulnerabilities like this one. Sign up free to get alerted when software you use is affected.
9.9

Cisco Catalyst SD-WAN Input Validation Weakness

CVE-2026-20303 · published 1 month ago
Summary

Cisco Catalyst SD-WAN software has a weakness in how it checks user input. This means an attacker could potentially manipulate data to cause issues. Cisco has released an update to fix this issue, and it's recommended to apply it as soon as possible.

What to do

The CVE record does not list a fixed version. Check the vendor's site or the advisory links below - a fix may already be released.

Affected software
VendorProductAffected versions
cisco cisco catalyst sd-wan controller 20.6.4
cisco cisco catalyst sd-wan manager 20.1.12
Original advisory text
Cisco Catalyst SD-WAN Security Hardening Release - Input Validation Vulnerabilities
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.
References
Severity
9.9 Critical
CVSS 3.1: 9.9 (MITRE)
Exploitation
EPSS <1%
Type
CWE-20Improper Input Validation
Timeline
Published5 Aug 2026
Updated1 Sep 2026
First seen5 Aug 2026
Sources
CVE-2026-20303 · NVD
CVE-2026-20303 · MITRE
Monitor software like this
Free during beta