CVE-2026-20146 Cisco CVE debrief

Who should care

Administrators of Cisco ISE and ISE-PIC systems, security teams, IT personnel responsible for patch management and system security, and operators managing affected deployments should prioritize patching, verify system integrity, and monitor for suspicious activity to prevent potential path traversal attacks and unauthorized file access or deletion.

Why it matters

CVE-2026-20146 vulnerability in Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC) allows authenticated remote attackers to perform path traversal attacks, potentially leading to unauthorized file access or deletion.

• Verify patch deployment to prevent path traversal attacks
• Monitor system logs for suspicious activity
• Restrict access to administrative credentials
• Implement additional security measures to detect and prevent similar attacks

Technical summary

The vulnerability is due to improper validation of user-supplied input in Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC). An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected system, potentially leading to path traversal attacks. A successful exploit could allow the attacker to access sensitive files or delete arbitrary files on the affected system. Administrators should prioritize patching and verify system integrity to prevent unauthorized file access or deletion.

Defensive priority

Administrators of Cisco ISE and ISE-PIC systems should prioritize patching, verify system integrity, and monitor for suspicious activity.

Recommended defensive actions

• Apply patches or updates provided by Cisco to vulnerable systems
• Verify system integrity and monitor for suspicious activity
• Restrict access to administrative credentials
• Implement additional security measures to detect and prevent similar attacks
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and NVD detail page provide information on the vulnerability, its impact, and affected versions. Cisco ISE and ISE-PIC are affected. Defenders should verify patch deployment, system integrity, and monitor for suspicious activity. Evidence is limited to public sources and may not reflect all affected versions or deployment contexts.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.