Attack Chain

1. An attacker authenticates to the Zyosoft School App using valid credentials.
2. The attacker identifies a request that includes a user-controlled parameter referencing a specific object (e.g., user ID, record number).
3. The attacker modifies the value of this parameter to reference a different object belonging to another user.
4. The attacker sends the modified request to the server.
5. The server, lacking proper authorization checks, processes the request using the attacker-supplied object reference.
6. The server returns the data associated with the targeted user’s object to the attacker.
7. The attacker can further modify parameters to alter the data of the targeted user.
8. The attacker successfully reads or modifies the targeted user’s data without proper authorization.

Impact

Successful exploitation of CVE-2026-7491 allows authenticated attackers to read and modify other users’ data within the Zyosoft School App. This can lead to severe consequences, including unauthorized access to sensitive student or staff information, modification of grades or attendance records, and potential data breaches. The number of affected users depends on the app’s deployment size, but any instance is vulnerable. This issue could affect any educational institution using the Zyosoft School App.

Recommendation

• Inspect web server logs for requests containing unusual parameter modifications, specifically those referencing user IDs or other sensitive data fields (webserver logs).
• Deploy the Sigma rule provided below to detect attempts to access or modify resources using potentially manipulated object references (Sigma rule).
• Implement robust authorization checks in the Zyosoft School App to verify that users only have access to resources they are explicitly authorized to access.
• Contact Zyosoft for a patch addressing CVE-2026-7491.