Improper Input Validation in Cisco Catalyst SD-WAN (CWE-20)
CVE-2026-20303 Published on August 5, 2026
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.
Vulnerability Analysis
CVE-2026-20303 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.
Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH
Weakness Type
Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
Products Associated with CVE-2026-20303
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Affected Versions
Cisco Catalyst SD-WAN Controller:- Version 20.6.4 is affected.
- Version 20.9.2 is affected.
- Version 20.3.6 is affected.
- Version 20.7.2 is affected.
- Version 20.7.1 is affected.
- Version 20.5.1 is affected.
- Version 20.6.2 is affected.
- Version 19.3.0 is affected.
- Version 20.6.1 is affected.
- Version 17.2.4 is affected.
- Version 18.2.0 is affected.
- Version 18.4.6 is affected.
- Version 19.1.0 is affected.
- Version 19.2.4 is affected.
- Version 19.2.929 is affected.
- Version 18.3.8 is affected.
- Version 18.4.303 is affected.
- Version 18.3.7 is affected.
- Version 18.4.1 is affected.
- Version 19.2.097 is affected.
- Version 19.2.0 is affected.
- Version 19.2.099 is affected.
- Version 18.3.6 is affected.
- Version 20.4.2 is affected.
- Version 19.0.0 is affected.
- Version 20.9.1 is affected.
- Version 20.3.5 is affected.
- Version 20.3.1 is affected.
- Version 18.3.5 is affected.
- Version 20.6.3 is affected.
- Version 18.4.3 is affected.
- Version 18.4.4 is affected.
- Version 18.3.3 is affected.
- Version 17.2.8 is affected.
- Version 20.8.1 is affected.
- Version 19.2.32 is affected.
- Version 19.2.2 is affected.
- Version 17.2.5 is affected.
- Version 18.4.0 is affected.
- Version 20.4.1.1 is affected.
- Version 20.1.3 is affected.
- Version 20.1.2 is affected.
- Version 17.2.10 is affected.
- Version 19.2.098 is affected.
- Version 20.1.1 is affected.
- Version 17.2.6 is affected.
- Version 19.2.1 is affected.
- Version 18.3.4 is affected.
- Version 20.4.1 is affected.
- Version 17.2.9 is affected.
- Version 19.2.31 is affected.
- Version 19.0.1a is affected.
- Version 18.3.0 is affected.
- Version 17.2.7 is affected.
- Version 18.4.5 is affected.
- Version 20.3.4 is affected.
- Version 20.3.3 is affected.
- Version 20.4.1.2 is affected.
- Version 20.3.2 is affected.
- Version 18.3.1 is affected.
- Version 20.1.12 is affected.
- Version 19.2.3 is affected.
- Version 20.10.1 is affected.
- Version 20.6.5 is affected.
- Version 20.3.7 is affected.
- Version 20.9.3 is affected.
- Version 20.11.1 is affected.
- Version 20.6.3.2 is affected.
- Version 20.4.2.3 is affected.
- Version 20.3.5.1 is affected.
- Version 20.3.4.3 is affected.
- Version 20.9.3.1 is affected.
- Version 20.6.4.1 is affected.
- Version 20.3.3.2 is affected.
- Version 20.6.5.2 is affected.
- Version 20.3.7.1 is affected.
- Version 20.11.1.1 is affected.
- Version 20.10.1.1 is affected.
- Version 20.6.1.2 is affected.
- Version 20.1.3.1 is affected.
- Version 20.9.2.2 is affected.
- Version 20.6.5.3 is affected.
- Version 20.6.3.3 is affected.
- Version 20.3.7.2 is affected.
- Version 20.6.5.4 is affected.
- Version 20.9.2.3 is affected.
- Version 20.9.4 is affected.
- Version 20.12.1 is affected.
- Version 20.3.8 is affected.
- Version 20.6.6 is affected.
- Version 20.12.2 is affected.
- Version 20.13.1 is affected.
- Version 20.9.5 is affected.
- Version 20.12.3 is affected.
- Version 20.6.7 is affected.
- Version 20.9.5.1 is affected.
- Version 20.14.1 is affected.
- Version 20.12.3.1 is affected.
- Version 20.12.4 is affected.
- Version 20.15.1 is affected.
- Version 20.9.6 is affected.
- Version 20.6.8 is affected.
- Version 20.16.1 is affected.
- Version 20.9.5.3 is affected.
- Version 20.12.4.1 is affected.
- Version 20.15.2 is affected.
- Version 20.12.5 is affected.
- Version 20.9.7 is affected.
- Version 20.15.3 is affected.
- Version 20.12.5.1 is affected.
- Version 20.12.5.2 is affected.
- Version 20.15.4 is affected.
- Version 20.9.7.1 is affected.
- Version 20.18.1 is affected.
- Version 20.12.6 is affected.
- Version 20.9.8 is affected.
- Version 20.15.4.1 is affected.
- Version 20.18.2 is affected.
- Version 26.1.1 is affected.
- Version 20.15.4.2 is affected.
- Version 20.18.2.1 is affected.
- Version 20.12.5.3 is affected.
- Version 20.12.6.1 is affected.
- Version 20.9.8.2 is affected.
- Version 20.15.5 is affected.
- Version 20.18.3 is affected.
- Version 20.12.7 is affected.
- Version 20.9.9 is affected.
- Version 20.18.2.2 is affected.
- Version 20.12.5.4 is affected.
- Version 20.12.7.1 is affected.
- Version 20.15.5.1 is affected.
- Version 20.15.4.3 is affected.
- Version 20.12.6.2 is affected.
- Version 20.15.5.2 is affected.
- Version 20.15.4.4 is affected.
- Version 26.1.1.1 is affected.
- Version 20.9.9.1 is affected.
- Version 20.18.3.1 is affected.
- Version 26.1.1.2 is affected.
- Version 20.15.4.5 is affected.
- Version 20.15.5.3 is affected.
- Version 20.12.7.2 is affected.
- Version 20.9.9.2 is affected.
- Version 20.15.6 is affected.
- Version 20.1.12 is affected.
- Version 19.2.1 is affected.
- Version 18.4.4 is affected.
- Version 18.4.5 is affected.
- Version 20.1.1.1 is affected.
- Version 20.1.1 is affected.
- Version 19.3.0 is affected.
- Version 19.2.2 is affected.
- Version 19.2.099 is affected.
- Version 18.3.6 is affected.
- Version 18.3.7 is affected.
- Version 19.2.0 is affected.
- Version 18.3.8 is affected.
- Version 19.0.0 is affected.
- Version 19.1.0 is affected.
- Version 18.4.302 is affected.
- Version 18.4.303 is affected.
- Version 19.2.097 is affected.
- Version 19.2.098 is affected.
- Version 17.2.10 is affected.
- Version 18.3.6.1 is affected.
- Version 19.0.1a is affected.
- Version 18.2.0 is affected.
- Version 18.4.3 is affected.
- Version 18.4.1 is affected.
- Version 17.2.8 is affected.
- Version 18.3.3.1 is affected.
- Version 18.4.0 is affected.
- Version 18.3.1 is affected.
- Version 17.2.6 is affected.
- Version 17.2.9 is affected.
- Version 18.3.4 is affected.
- Version 17.2.5 is affected.
- Version 18.3.1.1 is affected.
- Version 18.3.5 is affected.
- Version 18.4.0.1 is affected.
- Version 18.3.3 is affected.
- Version 17.2.7 is affected.
- Version 17.2.4 is affected.
- Version 18.3.0 is affected.
- Version 19.2.3 is affected.
- Version 18.4.501_ES is affected.
- Version 20.3.1 is affected.
- Version 20.1.2 is affected.
- Version 19.2.929 is affected.
- Version 19.2.31 is affected.
- Version 20.3.2 is affected.
- Version 19.2.32 is affected.
- Version 20.3.2_925 is affected.
- Version 20.3.2.1 is affected.
- Version 20.3.2.1_927 is affected.
- Version 18.4.6 is affected.
- Version 20.1.2_937 is affected.
- Version 20.4.1 is affected.
- Version 20.3.2_928 is affected.
- Version 20.3.2_929 is affected.
- Version 20.4.1.0.1 is affected.
- Version 20.3.2.1_930 is affected.
- Version 19.2.4 is affected.
- Version 20.5.0.1.1 is affected.
- Version 20.4.1.1 is affected.
- Version 20.3.3 is affected.
- Version 19.2.4.0.1 is affected.
- Version 20.3.2_937 is affected.
- Version 20.3.3.1 is affected.
- Version 20.5.1 is affected.
- Version 20.1.3 is affected.
- Version 20.3.3.0.4 is affected.
- Version 20.3.3.1.2 is affected.
- Version 20.3.3.1.1 is affected.
- Version 20.4.1.2 is affected.
- Version 20.3.3.0.2 is affected.
- Version 20.4.1.1.5 is affected.
- Version 20.4.1.0.01 is affected.
- Version 20.4.1.0.02 is affected.
- Version 20.3.3.1.7 is affected.
- Version 20.3.3.1.5 is affected.
- Version 20.5.1.0.1 is affected.
- Version 20.3.3.1.10 is affected.
- Version 20.3.3.0.8 is affected.
- Version 20.4.2 is affected.
- Version 20.4.2.0.1 is affected.
- Version 20.3.4 is affected.
- Version 20.3.3.0.14 is affected.
- Version 19.2.4.0.8 is affected.
- Version 19.2.4.0.9 is affected.
- Version 20.3.4.0.1 is affected.
- Version 20.3.2.0.5 is affected.
- Version 20.6.1 is affected.
- Version 20.5.1.0.2 is affected.
- Version 20.3.3.0.17 is affected.
- Version 20.6.1.1 is affected.
- Version 20.6.0.18.3 is affected.
- Version 20.3.2.0.6 is affected.
- Version 20.6.0.18.4 is affected.
- Version 20.4.2.0.2 is affected.
- Version 20.3.3.0.16 is affected.
- Version 20.3.4.0.5 is affected.
- Version 20.6.1.0.1 is affected.
- Version 20.3.4.0.6 is affected.
- Version 20.6.2 is affected.
- Version 20.7.1EFT2 is affected.
- Version 20.3.4.0.9 is affected.
- Version 20.3.4.0.11 is affected.
- Version 20.4.2.0.4 is affected.
- Version 20.3.3.0.18 is affected.
- Version 20.7.1 is affected.
- Version 20.6.2.1 is affected.
- Version 20.3.4.1 is affected.
- Version 20.5.1.1 is affected.
- Version 20.4.2.1 is affected.
- Version 20.4.2.1.1 is affected.
- Version 20.3.4.1.1 is affected.
- Version 20.3.813 is affected.
- Version 20.3.4.0.19 is affected.
- Version 20.4.2.2.1 is affected.
- Version 20.5.1.2 is affected.
- Version 20.3.4.2 is affected.
- Version 20.3.814 is affected.
- Version 20.4.2.2 is affected.
- Version 20.6.2.2 is affected.
- Version 20.3.4.2.1 is affected.
- Version 20.7.1.1 is affected.
- Version 20.3.4.1.2 is affected.
- Version 20.6.2.2.2 is affected.
- Version 20.3.4.0.20 is affected.
- Version 20.6.2.2.3 is affected.
- Version 20.4.2.2.2 is affected.
- Version 20.3.5 is affected.
- Version 20.6.2.0.4 is affected.
- Version 20.4.2.2.3 is affected.
- Version 20.3.4.0.24 is affected.
- Version 20.6.2.2.7 is affected.
- Version 20.6.3 is affected.
- Version 20.3.4.2.2 is affected.
- Version 20.4.2.2.4 is affected.
- Version 20.7.1.0.2 is affected.
- Version 20.8.1 is affected.
- Version 20.3.5.0.8 is affected.
- Version 20.3.5.0.9 is affected.
- Version 20.4.2.2.8 is affected.
- Version 20.3.5.0.7 is affected.
- Version 20.6.3.0.7 is affected.
- Version 20.6.3.0.5 is affected.
- Version 20.6.3.0.10 is affected.
- Version 20.6.3.0.2 is affected.
- Version 20.7.2 is affected.
- Version 20.9.1EFT2 is affected.
- Version 20.6.3.0.11 is affected.
- Version 20.6.3.1 is affected.
- Version 20.6.3.0.14 is affected.
- Version 20.6.4 is affected.
- Version 20.9.1 is affected.
- Version 20.6.3.0.19 is affected.
- Version 20.6.3.0.18 is affected.
- Version 20.3.6 is affected.
- Version 20.9.1.1 is affected.
- Version 20.6.3.0.23 is affected.
- Version 20.6.4.0.4 is affected.
- Version 20.6.3.0.25 is affected.
- Version 20.6.5 is affected.
- Version 20.6.3.0.27 is affected.
- Version 20.9.2 is affected.
- Version 20.9.2.1 is affected.
- Version 20.6.3.0.29 is affected.
- Version 20.6.3.0.31 is affected.
- Version 20.6.3.0.32 is affected.
- Version 20.10.1 is affected.
- Version 20.6.3.0.33 is affected.
- Version 20.9.2.0.01 is affected.
- Version 20.9.1_LI_Images is affected.
- Version 20.10.1_LI_Images is affected.
- Version 20.9.2_LI_Images is affected.
- Version 20.3.7 is affected.
- Version 20.9.3 is affected.
- Version 20.6.5.1 is affected.
- Version 20.11.1 is affected.
- Version 20.11.1_LI_Images is affected.
- Version 20.9.3_LI_ Images is affected.
- Version 20.6.3.1.1 is affected.
- Version 20.9.3.0.2 is affected.
- Version 20.6.5.1.2 is affected.
- Version 20.9.3.0.3 is affected.
- Version 20.4.2.3 is affected.
- Version 20.6.3.2 is affected.
- Version 20.6.4.1 is affected.
- Version 20.6.3.0.38 is affected.
- Version 20.6.3.0.39 is affected.
- Version 20.3.5.1 is affected.
- Version 20.3.4.3 is affected.
- Version 20.9.3.1 is affected.
- Version 20.3.3.2 is affected.
- Version 20.6.5.2 is affected.
- Version 20.3.7.1 is affected.
- Version 20.10.1.1 is affected.
- Version 20.6.5.2.1 is affected.
- Version 20.3.4.0.25 is affected.
- Version 20.6.2.2.4 is affected.
- Version 20.6.1.2 is affected.
- Version 20.11.1.1 is affected.
- Version 20.9.3.0.5 is affected.
- Version 20.3.4.0.26 is affected.
- Version 20.6.5.1.3 is affected.
- Version 20.6.3.0.40 is affected.
- Version 20.1.3.1 is affected.
- Version 20.9.2.2 is affected.
- Version 20.6.5.2.3 is affected.
- Version 20.6.5.1.4 is affected.
- Version 20.6.5.3 is affected.
- Version 20.6.3.0.41 is affected.
- Version 20.9.3.0.7 is affected.
- Version 20.6.5.1.5 is affected.
- Version 20.9.3.0.4 is affected.
- Version 20.6.4.0.19 is affected.
- Version 20.6.5.1.6 is affected.
- Version 20.9.3.0.8 is affected.
- Version 20.6.3.3 is affected.
- Version 20.3.7.2 is affected.
- Version 20.6.5.4 is affected.
- Version 20.6.5.1.7 is affected.
- Version 20.9.3.0.12 is affected.
- Version 20.6.4.2 is affected.
- Version 20.6.5.5 is affected.
- Version 20.9.3.2 is affected.
- Version 20.11.1.2 is affected.
- Version 20.6.3.4 is affected.
- Version 20.10.1.2 is affected.
- Version 20.6.5.1.9 is affected.
- Version 20.9.3.0.16 is affected.
- Version 20.6.3.0.45 is affected.
- Version 20.6.5.1.10 is affected.
- Version 20.9.3.0.17 is affected.
- Version 20.6.5.2.4 is affected.
- Version 20.6.4.0.21 is affected.
- Version 20.9.3.0.18 is affected.
- Version 20.6.3.0.46 is affected.
- Version 20.6.3.0.47 is affected.
- Version 20.9.2.3 is affected.
- Version 20.9.3.2_LI_Images is affected.
- Version 20.9.3.0.21 is affected.
- Version 20.9.3.0.20 is affected.
- Version 20.9.4_LI_Images is affected.
- Version 20.9.4 is affected.
- Version 20.6.5.1.11 is affected.
- Version 20.12.1 is affected.
- Version 20.12.1_LI_Images is affected.
- Version 20.6.5.1.13 is affected.
- Version 20.9.3.0.23 is affected.
- Version 20.6.5.2.8 is affected.
- Version 20.9.4.1 is affected.
- Version 20.9.4.1_LI_Images is affected.
- Version 20.9.3.0.25 is affected.
- Version 20.9.3.0.24 is affected.
- Version 20.6.5.1.14 is affected.
- Version 20.3.8 is affected.
- Version 20.6.6 is affected.
- Version 20.9.3.0.26 is affected.
- Version 20.6.3.0.51 is affected.
- Version 20.9.3.0.29 is affected.
- Version 20.12.2 is affected.
- Version 20.12.2_LI_Images is affected.
- Version 20.6.6.0.1 is affected.
- Version 20.13.1_LI_Images is affected.
- Version 20.9.4.0.4 is affected.
- Version 20.13.1 is affected.
- Version 20.9.4.1.1 is affected.
- Version 20.9.5 is affected.
- Version 20.9.5_LI_Images is affected.
- Version 20.12.3_LI_Images is affected.
- Version 20.12.3 is affected.
- Version 20.9.4.1.3 is affected.
- Version 20.6.7 is affected.
- Version 20.9.5.1 is affected.
- Version 20.9.5.1_LI_Images is affected.
- Version 20.9.4.1.6 is affected.
- Version 20.14.1 is affected.
- Version 20.14.1_LI_Images is affected.
- Version 20.9.5.2 is affected.
- Version 20.9.5.2.1 is affected.
- Version 20.9.5.2_LI_Images is affected.
- Version 20.12.3.1 is affected.
- Version 20.12.4 is affected.
- Version 20.15.1_LI_Images is affected.
- Version 20.15.1 is affected.
- Version 20.9.5.1.4 is affected.
- Version 20.9.5.2.7 is affected.
- Version 20.9.5.2.13 is affected.
- Version 20.9.6 is affected.
- Version 20.9.6_LI_Images is affected.
- Version 20.9.5.2.14 is affected.
- Version 20.6.8 is affected.
- Version 20.12.4.0.03 is affected.
- Version 20.16.1 is affected.
- Version 20.16.1_LI_Images is affected.
- Version 20.12.4_LI_Images is affected.
- Version 20.9.5.2.16 is affected.
- Version 20.12.4.0.4 is affected.
- Version 20.12.401 is affected.
- Version 20.9.5.3 is affected.
- Version 20.9.5.3_LI_Images is affected.
- Version 20.12.4.1_LI_Images is affected.
- Version 20.12.4.1 is affected.
- Version 20.9.5.2.21 is affected.
- Version 20.9.6.0.3 is affected.
- Version 20.12.4.0.6 is affected.
- Version 20.15.2_LI_Images is affected.
- Version 20.15.2 is affected.
- Version 20.12.4_Monthly_ES5 is affected.
- Version 20.12.5 is affected.
- Version 20.12.5_LI_Images is affected.
- Version 20.9.7_LI _Images is affected.
- Version 20.9.7 is affected.
- Version 20.15.3 is affected.
- Version 20.15.3_ LI _Images is affected.
- Version 20.12.501 is affected.
- Version 20.12.5.1_LI_Images is affected.
- Version 20.12.5.1 is affected.
- Version 20.12.5.2_LI_Images is affected.
- Version 20.12.5.2 is affected.
- Version 20.15.3.1 is affected.
- Version 20.15.4_LI_Images is affected.
- Version 20.15.4 is affected.
- Version 20.9.7.1_LI _Images is affected.
- Version 20.9.7.1 is affected.
- Version 20.18.1 is affected.
- Version 20.18.1_LI_Images is affected.
- Version 20.12.6_LI_Images is affected.
- Version 20.12.6 is affected.
- Version 20.12.5.1.01 is affected.
- Version 26.0.1 is affected.
- Version 20.9.8 is affected.
- Version 20.9.8_LI_Images is affected.
- Version 20.18.2 is affected.
- Version 20.15.4.1_LI_Images is affected.
- Version 20.15.4.1 is affected.
- Version 20.18.2_LI_Images is affected.
- Version 26.1.1 is affected.
- Version 26.1.1_LI_Images is affected.
- Version 20.18.2.1_LI_Images is affected.
- Version 20.18.2.1 is affected.
- Version 20.15.4.2_LI_Images is affected.
- Version 20.15.4.2 is affected.
- Version 20.12.6.1 is affected.
- Version 20.12.6.1_LI_Images is affected.
- Version 20.12.5.3 is affected.
- Version 20.12.5.3_LI_Images is affected.
- Version 20.9.8.2_LI_Images is affected.
- Version 20.9.8.2 is affected.
- Version 20.18.3 is affected.
- Version 20.18.3_LI_Images is affected.
- Version 20.15.5 is affected.
- Version 20.15.5_LI_Images is affected.
- Version 20.12.7 is affected.
- Version 20.12.7_LI_Images is affected.
- Version 20.9.9 is affected.
- Version 20.9.9_LI_Images is affected.
- Version 20.18.2.2 is affected.
- Version 20.18.2.2_LI_Images is affected.
- Version 20.12.5.4 is affected.
- Version 20.12.5.4_LI_ Images is affected.
- Version 20.12.7.1_LI_Images is affected.
- Version 20.12.6.2_LI_Images is affected.
- Version 20.12.7.1 is affected.
- Version 20.15.5.1 is affected.
- Version 20.15.4.3 is affected.
- Version 20.15.4.3_LI_Images is affected.
- Version 20.15.5.1_LI_Images is affected.
- Version 20.12.6.2 is affected.
- Version 20.15.5.2 is affected.
- Version 20.15.5.2_LI_Images is affected.
- Version 26.1.1.1_LI_Images is affected.
- Version 20.15.4.4 is affected.
- Version 20.15.4.4_LI_Images is affected.
- Version 26.1.1.1 is affected.
- Version 20.9.9.1_LI_Images is affected.
- Version 20.9.9.1 is affected.
- Version 20.18.3.1_LI_Images is affected.
- Version 20.18.3.1 is affected.
- Version 26.1.1.2 is affected.
- Version 26.1.1.2_LI_Images is affected.
- Version 20.15.4.5 is affected.
- Version 20.15.4.5_LI_Images is affected.
- Version 20.15.5.3 is affected.
- Version 20.15.5.3_LI_Images is affected.
- Version 20.12.7.2_LI_Images is affected.
- Version 20.12.7.2 is affected.
- Version 20.9.9.2 is affected.
- Version 20.9.9.2_LI_Images is affected.
- Version 20.15.6 is affected.
- Version 20.15.6_LI_Images is affected.