Cisco Zero-Day Highlights API Endpoint Authentication Issues

Cisco disclosed and patched a critical zero-day authentication bypass (CVE-2026-76460) in Identity Services Engine (ISE) and ISE Passive Identity Connector (ISE-PIC) that allows unauthenticated attackers to gain root privileges and command execution; the flaw is listed in CISA's Known Exploited Vulnerabilities catalog, affects ISE versions 3.1–3.5 (3.0 is unsupported), and Cisco urges patching and use of iACLs as temporary mitigation while recommending log review for potential IoCs.