Cisco Identity Services Engine (ISE) Critical Authentication Bypass Vulnerability (CVE-2026-76460)
Executive & SecOps Summary
SECOPS ASSESSMENTCisco Identity Services Engine (ISE) web-based management interface and API endpoints.
Unauthenticated remote attackers can gain full administrative access to the device by bypassing authentication controls.
Apply the latest security patches from Cisco immediately and restrict access to management interfaces via ACLs.
Affected Products & Version Scope
Remediation & Live Workaround Commands
PATCH & WORKAROUND- Immediate Patching: Upgrade to the fixed software version provided by Cisco via the official Software Central portal.
- Network Segmentation: Isolate the ISE management interface from general production traffic and ensure it is not reachable from the public internet.
- Implement Infrastructure ACLs: Restrict access to the management ports (e.g., TCP 443) to a dedicated management subnet.
# Example: Restricting management access via CLI
ip access-list standard RESTRICT_MGMT
permit 10.10.1.0 0.0.0.255
deny any- Log Analysis: Monitor ISE audit logs for suspicious API requests or unexpected administrative logins.
Stop Exposing VPN Ports to the Internet — Switch to Zero-Trust Access
Eliminate public-facing VPN concentrators and firewall management ports with identity-first Zero-Trust Network Access.
Technical Root Cause & Exploitation Mechanics
The vulnerability exists due to insufficient authentication validation on specific API endpoints within Cisco ISE. An attacker can exploit this by sending a specially crafted HTTP request to the affected endpoint, allowing them to bypass the authentication mechanism entirely. With a CVSS score of 10.0 and its inclusion in the CISA Known Exploited Vulnerabilities (KEV) catalog, this flaw represents a maximum-level risk. Successful exploitation grants the attacker unauthorized access to the web-based management interface, enabling them to manipulate network access policies, exfiltrate sensitive data, or facilitate lateral movement within the enterprise network.
Official Vendor Advisories & References
A vulnerability in an API of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to bypass authentication. This vulnerability is due to insufficient authentication control on an API endpoint. An attacker could exploit this vulnerability by sending a crafted request to an affected API endpoint. A successful exploit could allow the attacker to gain unauthorized access to the affected device by bypassing the web-based management interface.
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