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: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

The flaw results from improper input validation, classified under CWE-20. The vulnerability could allow an attacker with crafted input to influence the behavior of the Cisco Catalyst SD‑WAN Controller or Manager. The advisory does not describe the specific exploitation mechanism; however, the high CVSS score of 9.9 indicates a severe risk. Based on the score, it is inferred that the issue could potentially enable significant compromise of system functionality or data availability.

Affected Systems

This vulnerability affects Cisco Catalyst SD‑WAN Controller and Cisco Catalyst SD‑WAN Manager appliances. No specific firmware or software versions are identified in the advisory, so all existing deployments of these products should be considered vulnerable until an update is applied.

Risk and Exploitability

The CVSS score of 9.9 marks this issue as critical, and the lack of an EPSS score means the official probability of exploitation is not quantified. The advisory does not list the vulnerability in CISA’s KEV catalog. The advisory does not detail the attack vector. However, given typical exploitation of input‑validation vulnerabilities and the remote nature of SD‑WAN management interfaces, it is inferred that a remote attacker could potentially target exposed APIs or interfaces. No specific privileges beyond access to management interfaces appear required, so environments with unrestricted network access remain at elevated risk.

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.

Vendor Product Confidence Versions

Cisco

Catalyst Sd-wan Manager

91%

Version	Status	Scheme	Platform
`20.1.12`	affected	semver	—
`19.2.1`	affected	semver	—
`18.4.4`	affected	semver	—
`18.4.5`	affected	semver	—
`20.1.1.1`	affected	semver	—
`20.1.1`	affected	semver	—
`19.3.0`	affected	semver	—
`19.2.2`	affected	semver	—
`19.2.099`	affected	semver	—
`18.3.6`	affected	semver	—
`18.3.7`	affected	semver	—
`19.2.0`	affected	semver	—
`18.3.8`	affected	semver	—
`19.0.0`	affected	semver	—
`19.1.0`	affected	semver	—
`18.4.302`	affected	generic	—
`18.4.303`	affected	generic	—
`19.2.097`	affected	generic	—

Cisco

Cisco Catalyst Sd-wan Controller

100%

Version	Status	Scheme	Platform
`20.6.4`	affected	semver	—
`20.9.2`	affected	semver	—
`20.3.6`	affected	semver	—
`20.7.2`	affected	semver	—
`20.7.1`	affected	semver	—
`20.5.1`	affected	semver	—
`20.5.1.1`	affected	generic	—
`20.1.3`	affected	generic	—
`20.1.3.1`	affected	generic	—
`20.1.3.2`	affected	generic	—
`20.1.4`	affected	generic	—
`20.1.4.1`	affected	generic	—
`20.1.4.2`	affected	generic	—
`20.4.1`	affected	generic	—
`20.4.1.1`	affected	generic	—
`20.4.1.2`	affected	generic	—
`20.4.1.3`	affected	generic	—
`20.4.1.4`	affected	generic	—
`20.4.1.5`	affected	generic	—
`20.4.1.6`	affected	generic	—
`20.4.1.7`	affected	generic	—
`20.4.1.8`	affected	generic	—
`20.4.1.9`	affected	generic	—
`20.4.2`	affected	generic	—
`20.4.2.1`	affected	generic	—
`20.4.2.2`	affected	generic	—
`20.4.3`	affected	generic	—
`20.4.3.1`	affected	generic	—
`20.4.5`	affected	generic	—
`20.5.0`	affected	generic	—
`20.5.0.1`	affected	generic	—
`20.5.2`	affected	generic	—
`20.5.2.1`	affected	generic	—
`20.5.2.2`	affected	generic	—
`20.5.2.3`	affected	generic	—
`20.5.3`	affected	generic	—
`20.5.3.1`	affected	generic	—
`20.5.5`	affected	generic	—
`20.5.5.1`	affected	generic	—
`20.5.5.2`	affected	generic	—
`20.5.8`	affected	generic	—
`20.5.8.1`	affected	generic	—
`20.5.9`	affected	generic	—
`20.5.9.1`	affected	generic	—
`20.6.0`	affected	generic	—
`20.6.0.1`	affected	generic	—
`20.6.2`	affected	generic	—
`20.6.3`	affected	generic	—
`20.6.4.1`	affected	generic	—
`20.6.4.2`	affected	generic	—
`20.6.4.3`	affected	generic	—
`20.6.5`	affected	generic	—
`20.6.5.1`	affected	generic	—
`20.6.5.2`	affected	generic	—
`20.6.5.3`	affected	generic	—
`20.6.5.4`	affected	generic	—
`20.7.1`	affected	generic	—
`20.7.1.1`	affected	generic	—
`20.7.2`	affected	generic	—
`20.8.1`	affected	generic	—
`20.9.1`	affected	generic	—
`20.9.2`	affected	generic	—
`20.9.3`	affected	generic	—
`20.10.1`	affected	generic	—
`20.11.1`	affected	generic	—
`20.12.1`	affected	generic	—
`20.13.1`	affected	generic	—
`20.14.1`	affected	generic	—
`20.15.1`	affected	generic	—
`20.16.1`	affected	generic	—
`20.18.1`	affected	generic	—
`20.18.2`	affected	generic	—
`26.1.1`	affected	generic	—
`26.1.2`	affected	generic	—
`26.1.3`	affected	generic	—

Found an issue or want to improve our Enrichment? You can suggest it directly by opening an issue on our dedicated GitHub repository .

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

Update all Cisco Catalyst SD‑WAN Controller and Manager instances to the latest hardening release containing the input‑validation fix
Restrict or segment network access to the SD‑WAN Controller and Manager so that only trusted management hosts can reach them
Enforce strict input validation on all externally exposed endpoints, rejecting malformed or out‑of‑range data before processing
Enable and review logs for suspicious input handling failures to detect potential exploitation attempts

Generated by OpenCVE AI on August 5, 2026 at 19:06 UTC.

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.

The EPSS score is 0.00321.

Exploitation none

Automatable no

Technical Impact total

References

Link	Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-sdwan-faLcR3K
https://www.cve.org/Media/News/item/blog/2026/06/16/Preserving-Vulnerability-Level-Identification

History

Fri, 14 Aug 2026 21:30:00 +0000

Type	Values Removed	Values Added
References		https://www.cve.org/Media/News/item/blog/2026/06/16/Preserving-Vulnerability-Level-Identification

Fri, 07 Aug 2026 10:30:00 +0000

Type	Values Removed	Values Added
First Time appeared		Cisco Cisco catalyst Sd-wan Manager Cisco cisco Catalyst Sd-wan Controller
Vendors & Products		Cisco Cisco catalyst Sd-wan Manager Cisco cisco Catalyst Sd-wan Controller

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

Cisco Catalyst Sd-wan Manager Cisco Catalyst Sd-wan Controller

MITRE

Status: PUBLISHED

Assigner: cisco

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

Updated: 2026-08-14T21:00:51.494Z

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

Link: CVE-2026-20303

Vulnrichment

Updated: 2026-08-14T21:00:51.494Z

NVD

Status : Awaiting Analysis

Published: 2026-08-05T17:16:50.513

Modified: 2026-08-14T21:17:15.770

Link: CVE-2026-20303

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-08-07T10:05:52Z

Weaknesses

CWE-20
Improper Input Validation

Impact

Affected Systems

Risk and Exploitability

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

JSON object

JSON object

JSON object

JSON object

JSON object