CVE-2026-20195
Cisco Identity Services Engine Observable Response Discrepancy Vulnerability
MEDIUM 5.3
At a glance
- Source
- NVD
- EPSS
- EPSS 0.27 % · percentile 20 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- cisco
- NVD status
- Analyzed
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.
Weaknesses (CWE)
- CWE-204 — Observable Response Discrepancy
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N | cisco |
| CVSS 3.1 | MEDIUM 5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N | NVD · psirt@cisco.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-27863
- GCVE · GCVE-0-2026-20195
Affected configurations (NVD CPE)
cpe:2.3:a:cisco:identity_services_engine:*:*:*:*:*:*:*:*≤ 3.2.0cpe:2.3:a:cisco:identity_services_engine:3.3.0:-:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch1:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch10:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch2:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch3:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch4:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch5:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch6:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch7:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch8:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch9:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.4.0:-:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch1:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch2:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch3:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch4:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch5:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.5.0:-:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.5.0:patch1:*:*:*:*:*:*cpe:2.3:a:cisco:identity_services_engine:3.5.0:patch2:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Cisco · Cisco Identity Services Engine Software | affected 3.3.0 ; affected 3.3 Patch 2 ; affected 3.3 Patch 1 ; affected 3.3 Patch 3 ; affected 3.4.0 ; affected 3.3 Patch 4 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |