CVE-2026-20071
LowCVSS 3.8Exploitation Probability (EPSS)
Low risk4th percentile - higher than 4% of all known CVEs
Summary
A vulnerability in the SSID BYOD onboarding workflow of Cisco ISE is caused by insufficient authentication checks performed while a user is being onboarded. An unauthenticated, adjacent attacker can spoof the legitimate user and trigger a redirection to the guest web portal, hijacking the onboarding session.
Risk Assessment
An attacker could take over another user's session and gain access to the protected 802.1X network, potentially leading to unauthorized access to organizational resources.
Recommendation
Apply the available Cisco ISE updates that fix this vulnerability as soon as possible, and consider restricting access to the BYOD onboarding portal to trusted networks.
Other vulnerabilities in Cisco ISE
See all- CVE-2026-76423Critical
A vulnerability in the REST API of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to gain administrative access to an affected device. This is due to insufficient authorization checks in the REST API web service. An attacker can send crafted HTTP requests to the exposed REST API port to read and modify configuration and identity data with administrative privileges.
- CVE-2026-20307Critical
A vulnerability in the web-based management interface of Cisco ISE could allow an authenticated, remote attacker to execute arbitrary commands on the underlying operating system. The attacker must have at least low-privileged administrative credentials. The issue is due to insecure deserialization of a user-supplied Java byte stream; successful exploitation could allow code execution and privilege escalation to root, and in single-node deployments could cause the ISE node to become unavailable (DoS).
- CVE-2026-20306Critical
A vulnerability in the REST API of Cisco ISE and ISE-PIC could allow an authenticated, remote attacker to perform command injection attacks on the underlying operating system and elevate privileges to root. The attacker must have valid administrative credentials. The issue is due to improper validation of user-supplied input; successful exploitation could allow arbitrary code execution, and in single-node deployments could cause the ISE node to become unavailable (DoS).
- CVE-2026-20305Critical
A vulnerability in the diagnostic tools of Cisco ISE and ISE-PIC could allow an authenticated, remote attacker to perform command injection attacks on the underlying operating system and elevate privileges to root. The attacker must have valid administrative credentials. The issue is due to improper validation of user-supplied input; successful exploitation could allow arbitrary code execution, and in single-node deployments could cause the ISE node to become unavailable (DoS).
- CVE-2026-20234Critical
Cisco conducted an internal security review that resulted in a software hardening release addressing multiple internally discovered vulnerabilities in Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC). The vulnerabilities tracked by CVE-2026-20234 relate to insufficiently protected credentials (CWE-522).
- CVE-2026-20148Medium
A vulnerability in Cisco ISE and Cisco ISE-PIC allows an authenticated remote attacker to perform path traversal attacks on the underlying OS and read arbitrary files. The flaw is due to improper validation of user-supplied input.
- CVE-2026-20147Critical
A vulnerability in Cisco ISE and Cisco ISE-PIC allows an authenticated remote administrator to execute arbitrary commands on the underlying OS. The issue is due to insufficient input validation.
- CVE-2025-20337CriticalActively exploited
A vulnerability in a specific API of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to execute arbitrary code on the underlying operating system as root. The attacker does not require any valid credentials to exploit this vulnerability. This vulnerability is due to insufficient validation of user-supplied input.
- CVE-2026-76444Medium
A missing authentication vulnerability exists in the Policy Runtime Repository Table (PRRT) service of Cisco ISE and Cisco ISE-PIC. An unauthenticated remote attacker could send a crafted request to retrieve sensitive configuration information from an affected device.
- CVE-2026-76439Medium
Insufficient authentication on an internal interface exposed through the guest portal of Cisco ISE allows an unauthenticated remote attacker to submit forged posture status events into the endpoint posture pipeline. A crafted request can manipulate posture status on the affected system.
Original NVD description (English source)
A vulnerability in the SSID bring-your-own-device (BYOD) onboarding workflow of Cisco ISE could allow an unauthenticated, adjacent attacker to hijack the onboarding session of another user and access protected 802.1X networks. This vulnerability is due to insufficient authentication checks that are performed while a user is being onboarded. An attacker could exploit this vulnerability by spoofing the legitimate user and triggering a redirection to the guest web portal. A successful exploit could allow the attacker to take over the user session and gain access to the protected 802.1X network.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

