CVE-2026-20195Cisco Identity Services Engine Observable Response Discrepancy Vulnerability
- 5.3MediumCVSS base score
- 0.27%Exploitation in 30 daysEPSS · top 80% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By cisco
- 7 months later
· 7 months later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ciscoCNA (assigner) | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| NVDNVD · Analyzed | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.27% · top 80% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Affected products
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
- affected 3.4 Patch 1
- affected 3.3 Patch 5
- affected 3.3 Patch 6
- affected 3.4 Patch 2
- affected 3.3 Patch 7
- affected 3.4 Patch 3
- affected 3.5.0
- affected 3.4 Patch 4
- affected 3.3 Patch 8
- affected 3.5 Patch 1
- affected 3.3 Patch 9
- affected 3.4 Patch 5
- affected 3.5 Patch 3
- affected 3.5 Patch 2
- affected 3.3 Patch 10
What to do
Exploitation: The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-27863 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-20195)Record last updated .