CISA has added a critical authentication bypass vulnerability in Cisco Catalyst SD-WAN Manager, CVE-2026-76504 (CVSS 9.8), to its Known Exploited Vulnerabilities catalog. This flaw allows an unauthenticated, remote attacker to gain administrative access to an affected system. Active exploitation has been reported, making immediate patching crucial for organizations using Cisco Catalyst SD-WAN Manager. Defenders should also investigate for signs of prior compromise.