CVE-2026-66091
Unauthenticated IDOR Enables Disclosure of Other Users’ last-known details
In openEQUELLA before 2026.1, the GET /api/userquery/userinfobackup endpoint performs no authentication or authorisation check. An unauthenticated attacker who supplies another user's uniqueId can retrieve that user's stored personal details (username, first name, last name and email address) within the same institution.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.9
Unauthenticated IDOR Enables Disclosure of Other Users’ last-known details
In openEQUELLA before 2026.1, the GET /api/userquery/userinfobackup endpoint performs no authentication or authorisation check. An unauthenticated attacker who supplies another user's uniqueId can retrieve that user's stored personal details (username, first name, last name and email address) within the same institution.
- Record
CVE-2026-66091- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-639
- Updated
- 2026-11-02
EUVDEUVD-2026-112567
6.9
In openEQUELLA before 2026.1, the GET /api/userquery/userinfobackup endpoint performs no authentication or authorisation check. An unauthenticated attacker who supplies another user's uniqueId can retrieve that user's stored personal details (username, first name, last name and email address) within the same institution.
- Record
EUVD-2026-112567- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-gj26-grcq-vm8j
6.9
In openEQUELLA before 2026.1, the GET /api/userquery/userinfobackup endpoint performs no...
In openEQUELLA before 2026.1, the GET /api/userquery/userinfobackup endpoint performs no authentication or authorisation check. An unauthenticated attacker who supplies another user's uniqueId can retrieve that user's stored personal details (username, first name, last name and email address) within the same institution.
- Record
GHSA-gj26-grcq-vm8j- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-639
- Updated
- 2026-11-02
NVD
6.9
In openEQUELLA before 2026.1, the GET /api/userquery/userinfobackup endpoint performs no authentication or authorisation check. An unauthenticated attacker who supplies another user's uniqueId can retrieve that user's stored personal details (username, first name, last name and email address) within the same institution.
- Record
CVE-2026-66091- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-639
- Updated
- 2026-11-02
OSV
6.9
In openEQUELLA before 2026.1, the GET /api/userquery/userinfobackup endpoint performs no authentication or authorisation check. An unauthenticated attacker who supplies another user's uniqueId can retrieve that user's stored personal details (username, first name, last name and email address) within the same institution.
- Record
CVE-2026-66091- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-66091 is a medium vulnerability (CVSS 6.9) in Apereo Foundation Openequella, published October 29, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.40%, the 34th percentile. No source names a fixed version.