Auth Bypass in Grimmory-Tools 3.3.3 Download Endpoint via bookId
CVE-2026-93955 Published on September 19, 2026
grimmory-tools grimmory Download Endpoint KoboController.java streamFileToResponse authorization
A vulnerability was detected in grimmory-tools grimmory up to 3.3.3/3.4.1. Affected by this vulnerability is the function streamFileToResponse of the file backend/src/main/java/org/booklore/controller/KoboController.java of the component Download Endpoint. Performing a manipulation of the argument bookId results in authorization bypass. The attack may be initiated remotely. The exploit is now public and may be used. Issue #2431 is closed as completed, but its only comment states that the issue has already been reported elsewhere. No fixing commit or pull request is identified there.
Timeline
Advisory disclosed
VulDB entry created
VulDB entry last update
Weakness Types
What is an Insecure Direct Object Reference / IDOR Vulnerability?
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
CVE-2026-93955 has been classified to as an Insecure Direct Object Reference / IDOR vulnerability or weakness.
What is an AuthZ Vulnerability?
The software does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
CVE-2026-93955 has been classified to as an AuthZ vulnerability or weakness.
Products Associated with CVE-2026-93955
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Affected Versions
grimmory-tools grimmory:- Version 3.3.0 is affected.
- Version 3.3.1 is affected.
- Version 3.3.2 is affected.
- Version 3.3.3 is affected.
- Version 3.4.0 is affected.
- Version 3.4.1 is affected.