CVE-2026-20303 Cisco Catalyst SD-WAN Security Hardening Release - Input Validation Vulnerabilities
Cisco Catalyst SD-WAN Controller and Manager contain improper input validation vulnerabilities identified during internal security reviews.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-20303?
CVE-2026-20303 is a critical vulnerability in Cisco Catalyst SD-WAN Controller, published on 5 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-20
Which versions are affected by CVE-2026-20303?
How do I fix CVE-2026-20303?
No fix has been published for CVE-2026-20303 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-20303 being exploited?
There is no known exploitation of CVE-2026-20303 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-px9f-qgqp-xvc4.