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.

CVSS v3.1

9.9 CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS

0.32% chance of exploitation in the next 30 days, 25th percentile

Published

2026-08-05

Updated

2026-08-14

Proof-of-concept exploits (1)

• HORKimhab/Cisco-CVE-2026-20303-More0★ · 2026-08-27

References

• CVE Record
• NVD entry

Related

• CVE-2026-20262
• CVE-2026-20404
• CVE-2026-20253
• CVE-2026-20452
• CVE-2026-20251
• CVE-2026-2054