Cisco alerts customers to second actively exploited zero-day in as many days

A critical zero-day vulnerability (CVE-2026-76460) in Cisco's Identity Services Engine allows unauthenticated remote attackers to completely bypass authentication, seize device control, alter network policies, and exfiltrate credentials — all without prior access. The fact that this is the second actively exploited zero-day disclosed by Cisco in consecutive days underscores the urgency of maintaining aggressive patch cycles for network infrastructure components. ISE is a cornerstone of network access control, meaning a compromise here can cascade across an entire enterprise environment. CISA's addition to the Known Exploited Vulnerabilities (KEV) catalog confirms active in-the-wild exploitation, making delayed patching an unacceptable risk.