CVE-2026-66091— Unauthenticated IDOR Enables Disclosure of Other Users’ last-known details

Quick assessment

Affected

Apereo Foundation openEQUELLA

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

在 openEQUELLA 2026.1 之前的版本中，端点未执行任何身份验证或授权检查。未认证的攻击者若提供同一机构内其他用户的唯一标识符（uniqueId），即可获取该用户存储的个人信息（包括用户名、名、姓和电子邮件地址）。

CVSS 6.9 · Medium Updated Oct 29, 2026

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application

Get alerts for future matching vulnerabilities Log in to subscribe

Vulnerability Information

Have questions about the vulnerability? See if Shenlong's analysis helps!

View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title

Unauthenticated IDOR Enables Disclosure of Other Users’ last-known details

Source: CVE Program / CVE List V5

Vulnerability Description

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.

Source: CVE Program / CVE List V5

CVSS Information

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

Source: CVE Program / CVE List V5

Vulnerability Type

通过用户控制密钥绕过授权机制

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
Apereo Foundation	openEQUELLA	2019.2 ~ 2026.1	-

II. Public POCs for CVE-2026-66091

#	POC Description	Source Link	Shenlong Link

AI-Generated POC Premium

No public POC found.

III. Intelligence Information for CVE-2026-66091

请登录查看更多情报信息。

Other References for CVE-2026-66091 (2)

https://github.com/openequella/openEQUELLA/security/advisories/GHSA-mxj9-pmpw-j4xw vendor-advisory
https://openequella.github.io/guides/ product

https://www.cve.org/CVERecord?id=CVE-2026-66091

Same Patch Batch · Apereo Foundation · 2026-10-29 · 6 CVEs total

CVE-2026-66088	9.4 CRITICAL	Unrestricted Command Execution via system.execute
CVE-2026-66090	7.1 HIGH	XML External Entity (XXE) Injection in Metadata Field Allows Arbitrary File Read
CVE-2026-66089	6.1 MEDIUM	XML External Entity (XXE) Vulnerability in SOAP Interface Allows External Entity Expansion
CVE-2026-66092	4.8 MEDIUM	Stored XSS in pre-login notice via reachable legacy logon route
CVE-2026-16889	4.8 MEDIUM	Stored XSS via Pre-Login Notice Image Upload Serves Attacker HTML from Application Origin

IV. Related Vulnerabilities

Same product: openEQUELLA

Same vendor: Apereo Foundation

Same weakness: CWE-639