Cisco Warns of New Zero-Day ISE Auth Bypass (CVSS 10.0) Exploited in Active Attacks

Cisco disclosed CVE-2026-76460, a critical (CVSS 10.0) unauthenticated zero-day in Identity Services Engine (ISE) and ISE Passive Identity Connector that allows full authentication bypass and potential root command execution; Cisco confirmed active exploitation, published patches for supported ISE branches, advised re-imaging if compromise is suspected, and CISA added the flaw to its KEV catalog with an urgent patching deadline.