CVE-2026-76504

Description

A vulnerability in the API session-based authentication management of Cisco Catalyst SD-WAN Manager could allow an unauthenticated, remote attacker to access an affected system with privileges of the admin user. This vulnerability is due to improper handling of URI encoding in an HTTP request, which allows the request to bypass an authentication rule that is intended to restrict access to a specific API endpoint. An attacker could exploit this vulnerability by sending a crafted HTTP request to the API of the affected system. A successful exploit could allow the attacker to bypass authentication and gain access to the API as the admin user.

Scoring

• CVSS: 9.8 (CRITICAL, 3.1)
• EPSS exploitation probability: Not yet available
• EPSS percentile: Not yet available

CISA KEV status

• Added to KEV: 2026-09-30
• Remediation due date: 2026-10-03
• Known ransomware campaign use: Unknown

Weakness types (CWE)

• CWE-177

References

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sdwan-webauth-xr8beuuU
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-76504

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