Cisco Identity Services Engine Observable Response Discrepancy Vulnerability

Summary

CVE	CVE-2026-20195
State	PUBLISHED
Assigner	cisco
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-05-06 17:16:21 UTC
Updated	2026-05-06 18:59:53 UTC
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.

Risk And Classification

Primary CVSS: v3.1 5.3 MEDIUM from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Problem Types: CWE-204 | CWE-204 Observable Response Discrepancy

Version	Source	Type	Score	Severity	Vector
3.1	[email protected]	Primary	5.3	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`
3.1	CNA	CVSSV3_1	5.3	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`

CVSS v3.1 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.3.0	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.3 Patch 2	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.3 Patch 1	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.3 Patch 3	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.4.0	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.3 Patch 4	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.4 Patch 1	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.3 Patch 5	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.3 Patch 6	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.4 Patch 2	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.3 Patch 7	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.4 Patch 3	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.5.0	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.4 Patch 4	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.3 Patch 8	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.5 Patch 1	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.3 Patch 9	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.4 Patch 5	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.5 Patch 3	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.5 Patch 2	Not specified
CNA	Cisco	Cisco Identity Services Engine Software	affected 3.3 Patch 10	Not specified

References

Reference	Source	Link	Tags
sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-un...	[email protected]	sec.cloudapps.cisco.com
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

No vendor comments have been submitted for this CVE.

Additional Advisory Data

Exploits

CNA: The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.

There are currently no legacy QID mappings associated with this CVE.