Vulnerability Report

CVE-2026-20303

Title: Improper Input Validation in Cisco Catalyst SD-WAN

Input Validation Error

Proof Of Concept

PoC Available for CVE-2026-20303

CWE Category CWE-20
Published Date Aug 05, 2026
Modified Date Aug 14, 2026
Exploit Status Available
Score 9.9 CVSS v3.1
Exploit Probability (EPSS)
0.49%

Vulnerability Summary

CVE-2026-20303: 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.

Impacted Vendors

Analysis in Progress...

Reference Links

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-sdwan-faLcR3K
CVSS v3.1
Source Entity [email protected]
Severity CRITICAL
9.9
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
CHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-20303 Exploits & PoCs (Proof Of Concept)

GitHub https://github.com/HORKimhab/Cisco-CVE-2026-20303-More
View Code
MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected Stack

No specific products linked.