OTPulse

Cisco Identity Services Engine Authentication Bypass Vulnerabilities

MonitorCVSS 5.3cisco-sa-ise-multiauth-bypass-sgD2HbL4Sep 16, 2026
Cisco
IT in OT - Cisco networking products are commonly deployed in OT environments
Attack path
Attack VectorNetwork
Auth RequiredNone
ComplexityLow
User InteractionNone needed
Summary

Multiple authentication bypass vulnerabilities exist in Cisco Identity Services Engine (ISE) versions 3.1.0 through 3.5.0 and Cisco ISE Passive Identity Connector (ISE-PIC). Remote attackers can bypass authentication mechanisms to access or manipulate data without credentials, obtain sensitive configuration information, or force certificate and key material reloads on affected devices. The vulnerabilities affect both ISE administrative interfaces and user-facing components.

What this means
What could happen
An attacker could bypass authentication mechanisms in Cisco ISE to access or modify data without proper credentials, or trigger certificate/key reloads that could disrupt identity verification services.
Who's at risk
This impacts organizations using Cisco Identity Services Engine for network access control and authentication, particularly those relying on ISE for 802.1X enforcement, guest management, or device posture checking in enterprise networks with both IT and OT segments. Network administrators responsible for ISE deployments need to remediate immediately.
How it could be exploited
An attacker on the network could send specially crafted requests to the Cisco ISE admin or user portal without providing valid authentication credentials. If successful, the attacker gains access to ISE functions to read sensitive configuration data, modify user or device policies, or force a certificate reload.
Prerequisites
  • Network access to Cisco ISE administrative or user interfaces (typically port 443)
  • ISE version 3.1.0 through 3.5.0 deployed
  • No valid credentials required for exploitation
remotely exploitableno authentication requiredlow complexityaffects identity and access control
Exploitability
Unlikely to be exploited — EPSS score 0.4%
Affected products (1)
ProductAffected VersionsFix Status
Cisco Identity Services Engine3.1.0 through 3.5.0Fix available
Remediation & Mitigation
0/3
Do now
0/1
WORKAROUNDIf immediate patching is not possible, restrict network access to ISE administrative interfaces (port 443) to only trusted management networks using firewall rules
Schedule — requires maintenance window
0/1

Patching may require device reboot — plan for process interruption

HOTFIXUpdate Cisco Identity Services Engine to a patched version beyond 3.5.0 or the latest available patch release for your deployed version
Long-term hardening
0/1
HARDENINGImplement network segmentation to isolate ISE from untrusted networks and limit the blast radius if authentication is bypassed
View full vendor advisory
API: /api/v1/advisories/42054bc3-cf10-4322-aec0-b532127d8d39

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Cisco Identity Services Engine Authentication Bypass Vulnerabilities | CVSS 5.3 - OTPulse