CVE-2026-20303 - Vulnerability Details

- Cisco Catalyst SD-WAN Security Hardening Release - Input Validation Vulnerabilities

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.

Published: 2026-08-05

Score: 9.9 Critical

EPSS: n/a

KEV: No

Impact:

Action:

Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Cisco

Cisco Catalyst SD-WAN Controller

unknown

Version	Status	Constraints
`20.6.4`	affected	—
`20.9.2`	affected	—
`20.3.6`	affected	—
`20.7.2`	affected	—
`20.7.1`	affected	—
`20.5.1`	affected	—
`20.6.2`	affected	—
`19.3.0`	affected	—
`20.6.1`	affected	—
`17.2.4`	affected	—
`18.2.0`	affected	—
`18.4.6`	affected	—
`19.1.0`	affected	—
`19.2.4`	affected	—
`19.2.929`	affected	—
`18.3.8`	affected	—
`18.4.303`	affected	—
`18.3.7`	affected	—
`18.4.1`	affected	—
`19.2.097`	affected	—
`19.2.0`	affected	—
`19.2.099`	affected	—
`18.3.6`	affected	—
`20.4.2`	affected	—
`19.0.0`	affected	—
`20.9.1`	affected	—
`20.3.5`	affected	—
`20.3.1`	affected	—
`18.3.5`	affected	—
`20.6.3`	affected	—
`18.4.3`	affected	—
`18.4.4`	affected	—
`18.3.3`	affected	—
`17.2.8`	affected	—
`20.8.1`	affected	—
`19.2.32`	affected	—
`19.2.2`	affected	—
`17.2.5`	affected	—
`18.4.0`	affected	—
`20.4.1.1`	affected	—
`20.1.3`	affected	—
`20.1.2`	affected	—
`17.2.10`	affected	—
`19.2.098`	affected	—
`20.1.1`	affected	—
`17.2.6`	affected	—
`19.2.1`	affected	—
`18.3.4`	affected	—
`20.4.1`	affected	—
`17.2.9`	affected	—
`19.2.31`	affected	—
`19.0.1a`	affected	—
`18.3.0`	affected	—
`17.2.7`	affected	—
`18.4.5`	affected	—
`20.3.4`	affected	—
`20.3.3`	affected	—
`20.4.1.2`	affected	—
`20.3.2`	affected	—
`18.3.1`	affected	—
`20.1.12`	affected	—
`19.2.3`	affected	—
`20.10.1`	affected	—
`20.6.5`	affected	—
`20.3.7`	affected	—
`20.9.3`	affected	—
`20.11.1`	affected	—
`20.6.3.2`	affected	—
`20.4.2.3`	affected	—
`20.3.5.1`	affected	—
`20.3.4.3`	affected	—
`20.9.3.1`	affected	—
`20.6.4.1`	affected	—
`20.3.3.2`	affected	—
`20.6.5.2`	affected	—
`20.3.7.1`	affected	—
`20.11.1.1`	affected	—
`20.10.1.1`	affected	—
`20.6.1.2`	affected	—
`20.1.3.1`	affected	—
`20.9.2.2`	affected	—
`20.6.5.3`	affected	—
`20.6.3.3`	affected	—
`20.3.7.2`	affected	—
`20.6.5.4`	affected	—
`20.9.2.3`	affected	—
`20.9.4`	affected	—
`20.12.1`	affected	—
`20.3.8`	affected	—
`20.6.6`	affected	—
`20.12.2`	affected	—
`20.13.1`	affected	—
`20.9.5`	affected	—
`20.12.3`	affected	—
`20.6.7`	affected	—
`20.9.5.1`	affected	—
`20.14.1`	affected	—
`20.12.3.1`	affected	—
`20.12.4`	affected	—
`20.15.1`	affected	—
`20.9.6`	affected	—
`20.6.8`	affected	—
`20.16.1`	affected	—
`20.9.5.3`	affected	—
`20.12.4.1`	affected	—
`20.15.2`	affected	—
`20.12.5`	affected	—
`20.9.7`	affected	—
`20.15.3`	affected	—
`20.12.5.1`	affected	—
`20.12.5.2`	affected	—
`20.15.4`	affected	—
`20.9.7.1`	affected	—
`20.18.1`	affected	—
`20.12.6`	affected	—
`20.9.8`	affected	—
`20.15.4.1`	affected	—
`20.18.2`	affected	—
`26.1.1`	affected	—
`20.15.4.2`	affected	—
`20.18.2.1`	affected	—
`20.12.5.3`	affected	—
`20.12.6.1`	affected	—
`20.9.8.2`	affected	—
`20.15.5`	affected	—
`20.18.3`	affected	—
`20.12.7`	affected	—
`20.9.9`	affected	—
`20.18.2.2`	affected	—
`20.12.5.4`	affected	—
`20.12.7.1`	affected	—
`20.15.5.1`	affected	—
`20.15.4.3`	affected	—
`20.12.6.2`	affected	—
`20.15.5.2`	affected	—
`20.15.4.4`	affected	—
`26.1.1.1`	affected	—
`20.9.9.1`	affected	—
`20.18.3.1`	affected	—
`26.1.1.2`	affected	—
`20.15.4.5`	affected	—
`20.15.5.3`	affected	—
`20.12.7.2`	affected	—
`20.9.9.2`	affected	—
`20.15.6`	affected	—

Cisco

Cisco Catalyst SD-WAN Manager

unknown

Version	Status	Constraints
`20.1.12`	affected	—
`19.2.1`	affected	—
`18.4.4`	affected	—
`18.4.5`	affected	—
`20.1.1.1`	affected	—
`20.1.1`	affected	—
`19.3.0`	affected	—
`19.2.2`	affected	—
`19.2.099`	affected	—
`18.3.6`	affected	—
`18.3.7`	affected	—
`19.2.0`	affected	—
`18.3.8`	affected	—
`19.0.0`	affected	—
`19.1.0`	affected	—
`18.4.302`	affected	—
`18.4.303`	affected	—
`19.2.097`	affected	—
`19.2.098`	affected	—
`17.2.10`	affected	—
`18.3.6.1`	affected	—
`19.0.1a`	affected	—
`18.2.0`	affected	—
`18.4.3`	affected	—
`18.4.1`	affected	—
`17.2.8`	affected	—
`18.3.3.1`	affected	—
`18.4.0`	affected	—
`18.3.1`	affected	—
`17.2.6`	affected	—
`17.2.9`	affected	—
`18.3.4`	affected	—
`17.2.5`	affected	—
`18.3.1.1`	affected	—
`18.3.5`	affected	—
`18.4.0.1`	affected	—
`18.3.3`	affected	—
`17.2.7`	affected	—
`17.2.4`	affected	—
`18.3.0`	affected	—
`19.2.3`	affected	—
`18.4.501_ES`	affected	—
`20.3.1`	affected	—
`20.1.2`	affected	—
`19.2.929`	affected	—
`19.2.31`	affected	—
`20.3.2`	affected	—
`19.2.32`	affected	—
`20.3.2_925`	affected	—
`20.3.2.1`	affected	—
`20.3.2.1_927`	affected	—
`18.4.6`	affected	—
`20.1.2_937`	affected	—
`20.4.1`	affected	—
`20.3.2_928`	affected	—
`20.3.2_929`	affected	—
`20.4.1.0.1`	affected	—
`20.3.2.1_930`	affected	—
`19.2.4`	affected	—
`20.5.0.1.1`	affected	—
`20.4.1.1`	affected	—
`20.3.3`	affected	—
`19.2.4.0.1`	affected	—
`20.3.2_937`	affected	—
`20.3.3.1`	affected	—
`20.5.1`	affected	—
`20.1.3`	affected	—
`20.3.3.0.4`	affected	—
`20.3.3.1.2`	affected	—
`20.3.3.1.1`	affected	—
`20.4.1.2`	affected	—
`20.3.3.0.2`	affected	—
`20.4.1.1.5`	affected	—
`20.4.1.0.01`	affected	—
`20.4.1.0.02`	affected	—
`20.3.3.1.7`	affected	—
`20.3.3.1.5`	affected	—
`20.5.1.0.1`	affected	—
`20.3.3.1.10`	affected	—
`20.3.3.0.8`	affected	—
`20.4.2`	affected	—
`20.4.2.0.1`	affected	—
`20.3.4`	affected	—
`20.3.3.0.14`	affected	—
`19.2.4.0.8`	affected	—
`19.2.4.0.9`	affected	—
`20.3.4.0.1`	affected	—
`20.3.2.0.5`	affected	—
`20.6.1`	affected	—
`20.5.1.0.2`	affected	—
`20.3.3.0.17`	affected	—
`20.6.1.1`	affected	—
`20.6.0.18.3`	affected	—
`20.3.2.0.6`	affected	—
`20.6.0.18.4`	affected	—
`20.4.2.0.2`	affected	—
`20.3.3.0.16`	affected	—
`20.3.4.0.5`	affected	—
`20.6.1.0.1`	affected	—
`20.3.4.0.6`	affected	—
`20.6.2`	affected	—
`20.7.1EFT2`	affected	—
`20.3.4.0.9`	affected	—
`20.3.4.0.11`	affected	—
`20.4.2.0.4`	affected	—
`20.3.3.0.18`	affected	—
`20.7.1`	affected	—
`20.6.2.1`	affected	—
`20.3.4.1`	affected	—
`20.5.1.1`	affected	—
`20.4.2.1`	affected	—
`20.4.2.1.1`	affected	—
`20.3.4.1.1`	affected	—
`20.3.813`	affected	—
`20.3.4.0.19`	affected	—
`20.4.2.2.1`	affected	—
`20.5.1.2`	affected	—
`20.3.4.2`	affected	—
`20.3.814`	affected	—
`20.4.2.2`	affected	—
`20.6.2.2`	affected	—
`20.3.4.2.1`	affected	—
`20.7.1.1`	affected	—
`20.3.4.1.2`	affected	—
`20.6.2.2.2`	affected	—
`20.3.4.0.20`	affected	—
`20.6.2.2.3`	affected	—
`20.4.2.2.2`	affected	—
`20.3.5`	affected	—
`20.6.2.0.4`	affected	—
`20.4.2.2.3`	affected	—
`20.3.4.0.24`	affected	—
`20.6.2.2.7`	affected	—
`20.6.3`	affected	—
`20.3.4.2.2`	affected	—
`20.4.2.2.4`	affected	—
`20.7.1.0.2`	affected	—
`20.8.1`	affected	—
`20.3.5.0.8`	affected	—
`20.3.5.0.9`	affected	—
`20.4.2.2.8`	affected	—
`20.3.5.0.7`	affected	—
`20.6.3.0.7`	affected	—
`20.6.3.0.5`	affected	—
`20.6.3.0.10`	affected	—
`20.6.3.0.2`	affected	—
`20.7.2`	affected	—
`20.9.1EFT2`	affected	—
`20.6.3.0.11`	affected	—
`20.6.3.1`	affected	—
`20.6.3.0.14`	affected	—
`20.6.4`	affected	—
`20.9.1`	affected	—
`20.6.3.0.19`	affected	—
`20.6.3.0.18`	affected	—
`20.3.6`	affected	—
`20.9.1.1`	affected	—
`20.6.3.0.23`	affected	—
`20.6.4.0.4`	affected	—
`20.6.3.0.25`	affected	—
`20.6.5`	affected	—
`20.6.3.0.27`	affected	—
`20.9.2`	affected	—
`20.9.2.1`	affected	—
`20.6.3.0.29`	affected	—
`20.6.3.0.31`	affected	—
`20.6.3.0.32`	affected	—
`20.10.1`	affected	—
`20.6.3.0.33`	affected	—
`20.9.2.0.01`	affected	—
`20.9.1_LI_Images`	affected	—
`20.10.1_LI_Images`	affected	—
`20.9.2_LI_Images`	affected	—
`20.3.7`	affected	—
`20.9.3`	affected	—
`20.6.5.1`	affected	—
`20.11.1`	affected	—
`20.11.1_LI_Images`	affected	—
`20.9.3_LI_ Images`	affected	—
`20.6.3.1.1`	affected	—
`20.9.3.0.2`	affected	—
`20.6.5.1.2`	affected	—
`20.9.3.0.3`	affected	—
`20.4.2.3`	affected	—
`20.6.3.2`	affected	—
`20.6.4.1`	affected	—
`20.6.3.0.38`	affected	—
`20.6.3.0.39`	affected	—
`20.3.5.1`	affected	—
`20.3.4.3`	affected	—
`20.9.3.1`	affected	—
`20.3.3.2`	affected	—
`20.6.5.2`	affected	—
`20.3.7.1`	affected	—
`20.10.1.1`	affected	—
`20.6.5.2.1`	affected	—
`20.3.4.0.25`	affected	—
`20.6.2.2.4`	affected	—
`20.6.1.2`	affected	—
`20.11.1.1`	affected	—
`20.9.3.0.5`	affected	—
`20.3.4.0.26`	affected	—
`20.6.5.1.3`	affected	—
`20.6.3.0.40`	affected	—
`20.1.3.1`	affected	—
`20.9.2.2`	affected	—
`20.6.5.2.3`	affected	—
`20.6.5.1.4`	affected	—
`20.6.5.3`	affected	—
`20.6.3.0.41`	affected	—
`20.9.3.0.7`	affected	—
`20.6.5.1.5`	affected	—
`20.9.3.0.4`	affected	—
`20.6.4.0.19`	affected	—
`20.6.5.1.6`	affected	—
`20.9.3.0.8`	affected	—
`20.6.3.3`	affected	—
`20.3.7.2`	affected	—
`20.6.5.4`	affected	—
`20.6.5.1.7`	affected	—
`20.9.3.0.12`	affected	—
`20.6.4.2`	affected	—
`20.6.5.5`	affected	—
`20.9.3.2`	affected	—
`20.11.1.2`	affected	—
`20.6.3.4`	affected	—
`20.10.1.2`	affected	—
`20.6.5.1.9`	affected	—
`20.9.3.0.16`	affected	—
`20.6.3.0.45`	affected	—
`20.6.5.1.10`	affected	—
`20.9.3.0.17`	affected	—
`20.6.5.2.4`	affected	—
`20.6.4.0.21`	affected	—
`20.9.3.0.18`	affected	—
`20.6.3.0.46`	affected	—
`20.6.3.0.47`	affected	—
`20.9.2.3`	affected	—
`20.9.3.2_LI_Images`	affected	—
`20.9.3.0.21`	affected	—
`20.9.3.0.20`	affected	—
`20.9.4_LI_Images`	affected	—
`20.9.4`	affected	—
`20.6.5.1.11`	affected	—
`20.12.1`	affected	—
`20.12.1_LI_Images`	affected	—
`20.6.5.1.13`	affected	—
`20.9.3.0.23`	affected	—
`20.6.5.2.8`	affected	—
`20.9.4.1`	affected	—
`20.9.4.1_LI_Images`	affected	—
`20.9.3.0.25`	affected	—
`20.9.3.0.24`	affected	—
`20.6.5.1.14`	affected	—
`20.3.8`	affected	—
`20.6.6`	affected	—
`20.9.3.0.26`	affected	—
`20.6.3.0.51`	affected	—
`20.9.3.0.29`	affected	—
`20.12.2`	affected	—
`20.12.2_LI_Images`	affected	—
`20.6.6.0.1`	affected	—
`20.13.1_LI_Images`	affected	—
`20.9.4.0.4`	affected	—
`20.13.1`	affected	—
`20.9.4.1.1`	affected	—
`20.9.5`	affected	—
`20.9.5_LI_Images`	affected	—
`20.12.3_LI_Images`	affected	—
`20.12.3`	affected	—
`20.9.4.1.3`	affected	—
`20.6.7`	affected	—
`20.9.5.1`	affected	—
`20.9.5.1_LI_Images`	affected	—
`20.9.4.1.6`	affected	—
`20.14.1`	affected	—
`20.14.1_LI_Images`	affected	—
`20.9.5.2`	affected	—
`20.9.5.2.1`	affected	—
`20.9.5.2_LI_Images`	affected	—
`20.12.3.1`	affected	—
`20.12.4`	affected	—
`20.15.1_LI_Images`	affected	—
`20.15.1`	affected	—
`20.9.5.1.4`	affected	—
`20.9.5.2.7`	affected	—
`20.9.5.2.13`	affected	—
`20.9.6`	affected	—
`20.9.6_LI_Images`	affected	—
`20.9.5.2.14`	affected	—
`20.6.8`	affected	—
`20.12.4.0.03`	affected	—
`20.16.1`	affected	—
`20.16.1_LI_Images`	affected	—
`20.12.4_LI_Images`	affected	—
`20.9.5.2.16`	affected	—
`20.12.4.0.4`	affected	—
`20.12.401`	affected	—
`20.9.5.3`	affected	—
`20.9.5.3_LI_Images`	affected	—
`20.12.4.1_LI_Images`	affected	—
`20.12.4.1`	affected	—
`20.9.5.2.21`	affected	—
`20.9.6.0.3`	affected	—
`20.12.4.0.6`	affected	—
`20.15.2_LI_Images`	affected	—
`20.15.2`	affected	—
`20.12.4_Monthly_ES5`	affected	—
`20.12.5`	affected	—
`20.12.5_LI_Images`	affected	—
`20.9.7_LI _Images`	affected	—
`20.9.7`	affected	—
`20.15.3`	affected	—
`20.15.3_ LI _Images`	affected	—
`20.12.501`	affected	—
`20.12.5.1_LI_Images`	affected	—
`20.12.5.1`	affected	—
`20.12.5.2_LI_Images`	affected	—
`20.12.5.2`	affected	—
`20.15.3.1`	affected	—
`20.15.4_LI_Images`	affected	—
`20.15.4`	affected	—
`20.9.7.1_LI _Images`	affected	—
`20.9.7.1`	affected	—
`20.18.1`	affected	—
`20.18.1_LI_Images`	affected	—
`20.12.6_LI_Images`	affected	—
`20.12.6`	affected	—
`20.12.5.1.01`	affected	—
`26.0.1`	affected	—
`20.9.8`	affected	—
`20.9.8_LI_Images`	affected	—
`20.18.2`	affected	—
`20.15.4.1_LI_Images`	affected	—
`20.15.4.1`	affected	—
`20.18.2_LI_Images`	affected	—
`26.1.1`	affected	—
`26.1.1_LI_Images`	affected	—
`20.18.2.1_LI_Images`	affected	—
`20.18.2.1`	affected	—
`20.15.4.2_LI_Images`	affected	—
`20.15.4.2`	affected	—
`20.12.6.1`	affected	—
`20.12.6.1_LI_Images`	affected	—
`20.12.5.3`	affected	—
`20.12.5.3_LI_Images`	affected	—
`20.9.8.2_LI_Images`	affected	—
`20.9.8.2`	affected	—
`20.18.3`	affected	—
`20.18.3_LI_Images`	affected	—
`20.15.5`	affected	—
`20.15.5_LI_Images`	affected	—
`20.12.7`	affected	—
`20.12.7_LI_Images`	affected	—
`20.9.9`	affected	—
`20.9.9_LI_Images`	affected	—
`20.18.2.2`	affected	—
`20.18.2.2_LI_Images`	affected	—
`20.12.5.4`	affected	—
`20.12.5.4_LI_ Images`	affected	—
`20.12.7.1_LI_Images`	affected	—
`20.12.6.2_LI_Images`	affected	—
`20.12.7.1`	affected	—
`20.15.5.1`	affected	—
`20.15.4.3`	affected	—
`20.15.4.3_LI_Images`	affected	—
`20.15.5.1_LI_Images`	affected	—
`20.12.6.2`	affected	—
`20.15.5.2`	affected	—
`20.15.5.2_LI_Images`	affected	—
`26.1.1.1_LI_Images`	affected	—
`20.15.4.4`	affected	—
`20.15.4.4_LI_Images`	affected	—
`26.1.1.1`	affected	—
`20.9.9.1_LI_Images`	affected	—
`20.9.9.1`	affected	—
`20.18.3.1_LI_Images`	affected	—
`20.18.3.1`	affected	—
`26.1.1.2`	affected	—
`26.1.1.2_LI_Images`	affected	—
`20.15.4.5`	affected	—
`20.15.4.5_LI_Images`	affected	—
`20.15.5.3`	affected	—
`20.15.5.3_LI_Images`	affected	—
`20.12.7.2_LI_Images`	affected	—
`20.12.7.2`	affected	—
`20.9.9.2`	affected	—
`20.9.9.2_LI_Images`	affected	—
`20.15.6`	affected	—
`20.15.6_LI_Images`	affected	—

No data.

No data available yet.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable no

Technical Impact total

References

Link	Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-sdwan-faLcR3K

History

Wed, 05 Aug 2026 18:30:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

Wed, 05 Aug 2026 17:00:00 +0000

Type	Values Removed	Values Added
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.
Title		Cisco Catalyst SD-WAN Security Hardening Release - Input Validation Vulnerabilities
Weaknesses		CWE-20
References		https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-sdwan-faLcR3K
Metrics		cvssV3_1 `{'score': 9.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'}`

Subscriptions

No data.

MITRE

Status: PUBLISHED

Assigner: cisco

Published: 2026-08-05T16:29:52.593Z

Updated: 2026-08-05T17:45:12.920Z

Reserved: 2025-10-08T11:59:15.408Z

Link: CVE-2026-20303

Vulnrichment

Updated: 2026-08-05T17:38:56.268Z

NVD

No data.

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-08-05T19:15:03Z

Weaknesses

CWE-20

Tracking

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

Exploitation none

Automatable no

Technical Impact total

Subscriptions

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