Vulnerability · Published May 6, 2026 · Assigned by cisco
CVE-2026-20195Cisco Identity Services Engine Observable Response Discrepancy Vulnerability
Medium 5.3
In plain English
A medium-severity security flaw in Cisco Identity Services Engine Software from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Identity Services Engine Software | 3.3.03.3 Patch 23.3 Patch 13.3 Patch 33.4.03.3 Patch 43.4 Patch 13.3 Patch 5 |
Weakness: CWE-204 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N