Cisco Patches Critical Zero-Day Authentication Bypass in Catalyst SD-WAN Manager
Cisco Systems has released security updates to address a critical zero-day vulnerability in Cisco Catalyst SD-WAN Manager that allows attackers to bypass authentication and gain remote administrator access. The flaw, tracked as CVE-2026-76504, stems from improper URI encoding handling in HTTP requests targeting specific APIs. With a CVSS v3.1 base score of 9.8, the issue is rated Critical and has already been exploited in real-world attacks confirmed by Cisco in September 2026. The company published its security advisory on September 30, 2026, and strongly recommends immediate updates to the fixed releases. Organizations are also advised to restrict API access to trusted sources while applying the patches.
Security NEXTOct 1, 2026Translated from Japanese