CVE-2026-20303
CRITICALCVSS 9.9/10EPSS 0.29%
Last modified
CVE-2026-20303 is a critical-severity vulnerability rated 9.9/10 on the CVSS scale. 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.. EPSS estimates a 0.29% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Weakness Enumeration
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Catalyst SD-WAN Controller | 20.6.4; 20.9.2; 20.3.6; 20.7.2; 20.7.1; 20.5.1; 20.6.2; 19.3.0; 20.6.1; 17.2.4; 18.2.0; 18.4.6; 19.1.0; 19.2.4; 19.2.929; 18.3.8; 18.4.303; 18.3.7; 18.4.1; 19.2.097; 19.2.0; 19.2.099; 18.3.6; 20.4.2; 19.0.0; 20.9.1; 20.3.5; 20.3.1; 18.3.5; 20.6.3; 18.4.3; 18.4.4; 18.3.3; 17.2.8; 20.8.1; 19.2.32; 19.2.2; 17.2.5; 18.4.0; 20.4.1.1; 20.1.3; 20.1.2; 17.2.10; 19.2.098; 20.1.1; 17.2.6; 19.2.1; 18.3.4; 20.4.1; 17.2.9; 19.2.31; 19.0.1a; 18.3.0; 17.2.7; 18.4.5; 20.3.4; 20.3.3; 20.4.1.2; 20.3.2; 18.3.1; 20.1.12; 19.2.3; 20.10.1; 20.6.5; 20.3.7; 20.9.3; 20.11.1; 20.6.3.2; 20.4.2.3; 20.3.5.1; 20.3.4.3; 20.9.3.1; 20.6.4.1; 20.3.3.2; 20.6.5.2; 20.3.7.1; 20.11.1.1; 20.10.1.1; 20.6.1.2; 20.1.3.1; 20.9.2.2; 20.6.5.3; 20.6.3.3; 20.3.7.2; 20.6.5.4; 20.9.2.3; 20.9.4; 20.12.1; 20.3.8; 20.6.6; 20.12.2; 20.13.1; 20.9.5; 20.12.3; 20.6.7; 20.9.5.1; 20.14.1; 20.12.3.1; 20.12.4; 20.15.1; 20.9.6; 20.6.8; 20.16.1; 20.9.5.3; 20.12.4.1; 20.15.2; 20.12.5; 20.9.7; 20.15.3; 20.12.5.1; 20.12.5.2; 20.15.4; 20.9.7.1; 20.18.1; 20.12.6; 20.9.8; 20.15.4.1; 20.18.2; 26.1.1; 20.15.4.2; 20.18.2.1; 20.12.5.3; 20.12.6.1; 20.9.8.2; 20.15.5; 20.18.3; 20.12.7; 20.9.9; 20.18.2.2; 20.12.5.4; 20.12.7.1; 20.15.5.1; 20.15.4.3; 20.12.6.2; 20.15.5.2; 20.15.4.4; 26.1.1.1; 20.9.9.1; 20.18.3.1; 26.1.1.2; 20.15.4.5; 20.15.5.3; 20.12.7.2; 20.9.9.2; 20.15.6 |
| Cisco | Cisco Catalyst SD-WAN Manager | 20.1.12; 19.2.1; 18.4.4; 18.4.5; 20.1.1.1; 20.1.1; 19.3.0; 19.2.2; 19.2.099; 18.3.6; 18.3.7; 19.2.0; 18.3.8; 19.0.0; 19.1.0; 18.4.302; 18.4.303; 19.2.097; 19.2.098; 17.2.10; 18.3.6.1; 19.0.1a; 18.2.0; 18.4.3; 18.4.1; 17.2.8; 18.3.3.1; 18.4.0; 18.3.1; 17.2.6; 17.2.9; 18.3.4; 17.2.5; 18.3.1.1; 18.3.5; 18.4.0.1; 18.3.3; 17.2.7; 17.2.4; 18.3.0; 19.2.3; 18.4.501_ES; 20.3.1; 20.1.2; 19.2.929; 19.2.31; 20.3.2; 19.2.32; 20.3.2_925; 20.3.2.1; 20.3.2.1_927; 18.4.6; 20.1.2_937; 20.4.1; 20.3.2_928; 20.3.2_929; 20.4.1.0.1; 20.3.2.1_930; 19.2.4; 20.5.0.1.1; 20.4.1.1; 20.3.3; 19.2.4.0.1; 20.3.2_937; 20.3.3.1; 20.5.1; 20.1.3; 20.3.3.0.4; 20.3.3.1.2; 20.3.3.1.1; 20.4.1.2; 20.3.3.0.2; 20.4.1.1.5; 20.4.1.0.01; 20.4.1.0.02; 20.3.3.1.7; 20.3.3.1.5; 20.5.1.0.1; 20.3.3.1.10; 20.3.3.0.8; 20.4.2; 20.4.2.0.1; 20.3.4; 20.3.3.0.14; 19.2.4.0.8; 19.2.4.0.9; 20.3.4.0.1; 20.3.2.0.5; 20.6.1; 20.5.1.0.2; 20.3.3.0.17; 20.6.1.1; 20.6.0.18.3; 20.3.2.0.6; 20.6.0.18.4; 20.4.2.0.2; 20.3.3.0.16; 20.3.4.0.5; 20.6.1.0.1; 20.3.4.0.6; 20.6.2; 20.7.1EFT2; 20.3.4.0.9; 20.3.4.0.11; 20.4.2.0.4; 20.3.3.0.18; 20.7.1; 20.6.2.1; 20.3.4.1; 20.5.1.1; 20.4.2.1; 20.4.2.1.1; 20.3.4.1.1; 20.3.813; 20.3.4.0.19; 20.4.2.2.1; 20.5.1.2; 20.3.4.2; 20.3.814; 20.4.2.2; 20.6.2.2; 20.3.4.2.1; 20.7.1.1; 20.3.4.1.2; 20.6.2.2.2; 20.3.4.0.20; 20.6.2.2.3; 20.4.2.2.2; 20.3.5; 20.6.2.0.4; 20.4.2.2.3; 20.3.4.0.24; 20.6.2.2.7; 20.6.3; 20.3.4.2.2; 20.4.2.2.4; 20.7.1.0.2; 20.8.1; 20.3.5.0.8; 20.3.5.0.9; 20.4.2.2.8; 20.3.5.0.7; 20.6.3.0.7; 20.6.3.0.5; 20.6.3.0.10; 20.6.3.0.2; 20.7.2; 20.9.1EFT2; 20.6.3.0.11; 20.6.3.1; 20.6.3.0.14; 20.6.4; 20.9.1; 20.6.3.0.19; 20.6.3.0.18; 20.3.6; 20.9.1.1; 20.6.3.0.23; 20.6.4.0.4; 20.6.3.0.25; 20.6.5; 20.6.3.0.27; 20.9.2; 20.9.2.1; 20.6.3.0.29; 20.6.3.0.31; 20.6.3.0.32; 20.10.1; 20.6.3.0.33; 20.9.2.0.01; 20.9.1_LI_Images; 20.10.1_LI_Images; 20.9.2_LI_Images; 20.3.7; 20.9.3; 20.6.5.1; 20.11.1; 20.11.1_LI_Images; 20.9.3_LI_ Images; 20.6.3.1.1; 20.9.3.0.2; 20.6.5.1.2; 20.9.3.0.3; 20.4.2.3; 20.6.3.2; 20.6.4.1; 20.6.3.0.38; 20.6.3.0.39; 20.3.5.1; 20.3.4.3; 20.9.3.1; 20.3.3.2; 20.6.5.2; 20.3.7.1; 20.10.1.1; 20.6.5.2.1; 20.3.4.0.25; 20.6.2.2.4; 20.6.1.2; 20.11.1.1; 20.9.3.0.5; 20.3.4.0.26; 20.6.5.1.3; 20.6.3.0.40; 20.1.3.1; 20.9.2.2; 20.6.5.2.3; 20.6.5.1.4; 20.6.5.3; 20.6.3.0.41; 20.9.3.0.7; 20.6.5.1.5; 20.9.3.0.4; 20.6.4.0.19; 20.6.5.1.6; 20.9.3.0.8; 20.6.3.3; 20.3.7.2; 20.6.5.4; 20.6.5.1.7; 20.9.3.0.12; 20.6.4.2; 20.6.5.5; 20.9.3.2; 20.11.1.2; 20.6.3.4; 20.10.1.2; 20.6.5.1.9; 20.9.3.0.16; 20.6.3.0.45; 20.6.5.1.10; 20.9.3.0.17; 20.6.5.2.4; 20.6.4.0.21; 20.9.3.0.18; 20.6.3.0.46; 20.6.3.0.47; 20.9.2.3; 20.9.3.2_LI_Images; 20.9.3.0.21; 20.9.3.0.20; 20.9.4_LI_Images; 20.9.4; 20.6.5.1.11; 20.12.1; 20.12.1_LI_Images; 20.6.5.1.13; 20.9.3.0.23; 20.6.5.2.8; 20.9.4.1; 20.9.4.1_LI_Images; 20.9.3.0.25; 20.9.3.0.24; 20.6.5.1.14; 20.3.8; 20.6.6; 20.9.3.0.26; 20.6.3.0.51; 20.9.3.0.29; 20.12.2; 20.12.2_LI_Images; 20.6.6.0.1; 20.13.1_LI_Images; 20.9.4.0.4; 20.13.1; 20.9.4.1.1; 20.9.5; 20.9.5_LI_Images; 20.12.3_LI_Images; 20.12.3; 20.9.4.1.3; 20.6.7; 20.9.5.1; 20.9.5.1_LI_Images; 20.9.4.1.6; 20.14.1; 20.14.1_LI_Images; 20.9.5.2; 20.9.5.2.1; 20.9.5.2_LI_Images; 20.12.3.1; 20.12.4; 20.15.1_LI_Images; 20.15.1; 20.9.5.1.4; 20.9.5.2.7; 20.9.5.2.13; 20.9.6; 20.9.6_LI_Images; 20.9.5.2.14; 20.6.8; 20.12.4.0.03; 20.16.1; 20.16.1_LI_Images; 20.12.4_LI_Images; 20.9.5.2.16; 20.12.4.0.4; 20.12.401; 20.9.5.3; 20.9.5.3_LI_Images; 20.12.4.1_LI_Images; 20.12.4.1; 20.9.5.2.21; 20.9.6.0.3; 20.12.4.0.6; 20.15.2_LI_Images; 20.15.2; 20.12.4_Monthly_ES5; 20.12.5; 20.12.5_LI_Images; 20.9.7_LI _Images; 20.9.7; 20.15.3; 20.15.3_ LI _Images; 20.12.501; 20.12.5.1_LI_Images; 20.12.5.1; 20.12.5.2_LI_Images; 20.12.5.2; 20.15.3.1; 20.15.4_LI_Images; 20.15.4; 20.9.7.1_LI _Images; 20.9.7.1; 20.18.1; 20.18.1_LI_Images; 20.12.6_LI_Images; 20.12.6; 20.12.5.1.01; 26.0.1; 20.9.8; 20.9.8_LI_Images; 20.18.2; 20.15.4.1_LI_Images; 20.15.4.1; 20.18.2_LI_Images; 26.1.1; 26.1.1_LI_Images; 20.18.2.1_LI_Images; 20.18.2.1; 20.15.4.2_LI_Images; 20.15.4.2; 20.12.6.1; 20.12.6.1_LI_Images; 20.12.5.3; 20.12.5.3_LI_Images; 20.9.8.2_LI_Images; 20.9.8.2; 20.18.3; 20.18.3_LI_Images; 20.15.5; 20.15.5_LI_Images; 20.12.7; 20.12.7_LI_Images; 20.9.9; 20.9.9_LI_Images; 20.18.2.2; 20.18.2.2_LI_Images; 20.12.5.4; 20.12.5.4_LI_ Images; 20.12.7.1_LI_Images; 20.12.6.2_LI_Images; 20.12.7.1; 20.15.5.1; 20.15.4.3; 20.15.4.3_LI_Images; 20.15.5.1_LI_Images; 20.12.6.2; 20.15.5.2; 20.15.5.2_LI_Images; 26.1.1.1_LI_Images; 20.15.4.4; 20.15.4.4_LI_Images; 26.1.1.1; 20.9.9.1_LI_Images; 20.9.9.1; 20.18.3.1_LI_Images; 20.18.3.1; 26.1.1.2; 26.1.1.2_LI_Images; 20.15.4.5; 20.15.4.5_LI_Images; 20.15.5.3; 20.15.5.3_LI_Images; 20.12.7.2_LI_Images; 20.12.7.2; 20.9.9.2; 20.9.9.2_LI_Images; 20.15.6; 20.15.6_LI_Images |
References
Timeline
- Published
- Last Modified
- Status
- Awaiting Analysis
Frequently Asked Questions
What is 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.
How severe is CVE-2026-20303?
CVE-2026-20303 has a CVSS score of 9.9/10 (CRITICAL severity). The EPSS model estimates a 0.29% probability of exploitation in the next 30 days.
How do I fix CVE-2026-20303?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
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Are you affected by CVE-2026-20303?
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