Cisco Identity Services Engine Observable Response Discrepancy Vulnerability
Priority LOW 30CWE-204Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-204.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00275 19th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Cisco | Cisco Identity Services Engine Software | 3.3.0; 3.3 Patch 2; 3.3 Patch 1; 3.3 Patch 3; 3.4.0; 3.3 Patch 4; 3.4 Patch 1; 3.3 Patch 5; 3.3 Patch 6; 3.4 Patch 2; 3.3 Patch 7; 3.4 Patch 3; 3.5.0; 3.4 Patch 4; 3.3 Patch 8; 3.5 Patch 1; 3.3 Patch 9; 3.4 Patch 5; 3.5 Patch 3; 3.5 Patch 2; 3.3 Patch 10 | — | No fix listed | CNA |
- Cisco Identity Services Engine Software VendorCisco Affected 3.3.0; 3.3 Patch 2; 3.3 Patch 1; 3.3 Patch 3; 3.4.0; 3.3 Patch 4; 3.4 Patch 1; 3.3 Patch 5; 3.3 Patch 6; 3.4 Patch 2; 3.3 Patch 7; 3.4 Patch 3; 3.5.0; 3.4 Patch 4; 3.3 Patch 8; 3.5 Patch 1; 3.3 Patch 9; 3.4 Patch 5; 3.5 Patch 3; 3.5 Patch 2; 3.3 Patch 10 Fixed in — No fix listed CNA
CPE configurations NVD · 21
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:cisco:identity_services_engine:*:*:*:*:*:*:*:* | up to 3.2.0 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.3.0:-:*:*:*:*:*:* | 3.3.0 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch1:*:*:*:*:*:* | 3.3.0 patch1 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch10:*:*:*:*:*:* | 3.3.0 patch10 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch2:*:*:*:*:*:* | 3.3.0 patch2 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch3:*:*:*:*:*:* | 3.3.0 patch3 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch4:*:*:*:*:*:* | 3.3.0 patch4 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch5:*:*:*:*:*:* | 3.3.0 patch5 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch6:*:*:*:*:*:* | 3.3.0 patch6 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch7:*:*:*:*:*:* | 3.3.0 patch7 | Vulnerable | Cisco |
- cpe:2.3:a:cisco:identity_services_engine:*:*:*:*:*:*:*:* Versions up to 3.2.0 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.3.0:-:*:*:*:*:*:* Versions 3.3.0 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch1:*:*:*:*:*:* Versions 3.3.0 patch1 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch10:*:*:*:*:*:* Versions 3.3.0 patch10 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch2:*:*:*:*:*:* Versions 3.3.0 patch2 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch3:*:*:*:*:*:* Versions 3.3.0 patch3 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch4:*:*:*:*:*:* Versions 3.3.0 patch4 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch5:*:*:*:*:*:* Versions 3.3.0 patch5 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch6:*:*:*:*:*:* Versions 3.3.0 patch6 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch7:*:*:*:*:*:* Versions 3.3.0 patch7 Vulnerable ·Cisco
Show 11 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch8:*:*:*:*:*:* | 3.3.0 patch8 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch9:*:*:*:*:*:* | 3.3.0 patch9 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.4.0:-:*:*:*:*:*:* | 3.4.0 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch1:*:*:*:*:*:* | 3.4.0 patch1 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch2:*:*:*:*:*:* | 3.4.0 patch2 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch3:*:*:*:*:*:* | 3.4.0 patch3 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch4:*:*:*:*:*:* | 3.4.0 patch4 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch5:*:*:*:*:*:* | 3.4.0 patch5 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.5.0:-:*:*:*:*:*:* | 3.5.0 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.5.0:patch1:*:*:*:*:*:* | 3.5.0 patch1 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:identity_services_engine:3.5.0:patch2:*:*:*:*:*:* | 3.5.0 patch2 | Vulnerable | Cisco |
- cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch8:*:*:*:*:*:* Versions 3.3.0 patch8 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.3.0:patch9:*:*:*:*:*:* Versions 3.3.0 patch9 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.4.0:-:*:*:*:*:*:* Versions 3.4.0 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch1:*:*:*:*:*:* Versions 3.4.0 patch1 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch2:*:*:*:*:*:* Versions 3.4.0 patch2 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch3:*:*:*:*:*:* Versions 3.4.0 patch3 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch4:*:*:*:*:*:* Versions 3.4.0 patch4 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.4.0:patch5:*:*:*:*:*:* Versions 3.4.0 patch5 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.5.0:-:*:*:*:*:*:* Versions 3.5.0 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.5.0:patch1:*:*:*:*:*:* Versions 3.5.0 patch1 Vulnerable ·Cisco
- cpe:2.3:a:cisco:identity_services_engine:3.5.0:patch2:*:*:*:*:*:* Versions 3.5.0 patch2 Vulnerable ·Cisco
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-20195
- 2026-10-03 Alias added: GHSA-63pc-j336-8qq4
References
Advisory 1
More Cisco Identity Services Engine vulnerabilities
- TI-2026-53488 Cisco Identity Services Engine Authentication Bypass Vulnerability KEVCVSS 3.1CRITICAL 10.0
- TI-2025-14632 Cisco ISE API Unauthenticated Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 10.0
- TI-2025-14578 Cisco ISE API Unauthenticated Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 10.0
- TI-2021-19919 Apache Log4j2 JNDI features do not protect against attacker controlled LDAP and other JNDI related endpoints KEVCVSS 3.1CRITICAL 10.0
- TI-2025-14579 Cisco ISE API Unauthenticated Remote Code Execution Vulnerability CVSS 3.1CRITICAL 10.0
- TI-2022-05522 OS command injection in Cisco Identity Services Engine Software CVSS 3.1HIGH 8.8
Sources
- CVE-2026-20195 · CVE Program
- CVE-2026-20195 · NVD
- FIRST EPSS
- GHSA-63pc-j336-8qq4 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences