CVE-2026-20195
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk19th percentile - higher than 19% of all known CVEs
Summary
A vulnerability in an identity management API endpoint of Cisco ISE allows an unauthenticated, remote attacker to enumerate valid user accounts on an affected device. The issue exists due to observable error messages when the API endpoint is called.
Risk Assessment
An attacker can compile a list of valid usernames, facilitating brute-force or social engineering attacks against the system.
Recommendation
Apply the patches provided by Cisco immediately and restrict access to the identity management API endpoint to trusted networks only.
Other vulnerabilities in Cisco ISE
See all- 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-2026-20193Medium
A vulnerability in the RADIUS Policy API endpoints of Cisco ISE allows an authenticated, remote attacker with read-only Administrator privileges to gain unauthorized access to sensitive information. This is due to improper role-based access control (RBAC) permissions on these API endpoints.
Original NVD description (English source)
A vulnerability in an identity management API endpoint of Cisco ISE could allow an unauthenticated, remote attacker to enumerate valid user accounts on an affected device. This vulnerability exists because error messages are observed when the affected API endpoint is called. An attacker could exploit this vulnerability by sending a series of crafted requests to the affected endpoint and analyzing the differentiated responses. A successful exploit could allow the attacker to compile a list of valid usernames on an affected system.