VulnTideExploited vulnerabilities, by vendor. Data as of .
Not in CISA KEVPublished CVSS 9.9 criticalEPSS 0.5% probability of exploitation in 30 days
Cisco

CVE-2026-20303: Cisco Catalyst SD-WAN Security Hardening Release - Input Validation Vulnerabilities

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?
0.5%

EPSS score, percentile 41.8 of all scored records. A probability estimated by FIRST, not a report of exploitation.

How severe?
9.9 Critical

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

  • 20.6.4
  • 20.9.2
  • 20.3.6
  • 20.7.2
  • 20.7.1
  • 20.5.1

and 18 more in the table below

Versions by product

Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Cisco Cisco Catalyst SD-WAN Controller
StatusVersions
Affected20.6.4
Affected20.9.2
Affected20.3.6
Affected20.7.2
Affected20.7.1
Affected20.5.1
Affected20.6.2
Affected19.3.0
Affected20.6.1
Affected17.2.4
Affected18.2.0
Affected18.4.6

Versions not listed are: unknown.

And 133 more version entries in the CVE record.

Cisco Cisco Catalyst SD-WAN Manager
StatusVersions
Affected20.1.12
Affected19.2.1
Affected18.4.4
Affected18.4.5
Affected20.1.1.1
Affected20.1.1
Affected19.3.0
Affected19.2.2
Affected19.2.099
Affected18.3.6
Affected18.3.7
Affected19.2.0

Versions not listed are: unknown.

And 378 more version entries in the CVE record.

Source: CVE List, as of . About the data.

About this vulnerability

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…

Summary: CVE record, as of .

  • CISA has not added CVE-2026-20303 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
  • The CVE record was published on 5 Aug 2026.
  • The CVE record carries a CVSS v3.1 base score of 9.9 (Critical), given by its CNA.
  • FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.5% (percentile 41.8), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
  • CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact total.

Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.

Description

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.

Source: CVE List, as of . About the data.

Weakness

CWE-20

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.

Timeline

DateEvent
CVE record published
CVE record last updated

References

1

Known exploited Cisco vulnerabilities

  • CVE-2026-76418: Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability (added )
  • CVE-2026-76519: Cisco Secure Email Gateway Relative Path Traversal Vulnerability (added )
  • CVE-2026-76504: Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability (added )
  • CVE-2026-76460: Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability (added )
  • CVE-2026-76461: Cisco Secure Email Gateway SQL Injection Vulnerability (added )