CVE-2026-93955

Deferred Deferred - Pending Action

Authorization Bypass in grimmory-tools grimmory

Publication date: 2026-09-19

Last updated on: 2026-09-19

Assigner: VulDB

Description

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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-19

Last Modified

2026-09-19

Generated

2026-09-20

AI Q&A

2026-09-20

EPSS Evaluated

N/A

NVD

CVE-2026-93955

Affected Vendors & Products

Vendor	Product	Version / Range
grimmory	grimmory	to 3.4.1 (inc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-285	The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
CWE-639	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.

Attack-Flow Graph

Executive Summary

This vulnerability is an authorization bypass in the grimmory-tools grimmory software up to version 3.3.3/3.4.1. It exists in the streamFileToResponse function of the KoboController.java file within the Download Endpoint component. By manipulating the bookId argument, an attacker can bypass authorization checks and access restricted files remotely.

Impact Analysis

This vulnerability allows remote attackers to access unauthorized files by manipulating the bookId parameter. If exploited, it could lead to exposure of sensitive data, unauthorized downloads, or further system compromise depending on the application's context and data stored.

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, which may violate compliance requirements under GDPR (data protection) and HIPAA (health information privacy). Organizations using affected software may face regulatory penalties, data breach notifications, and reputational damage if exploited.

Mitigation Strategies

Immediately update grimmory-tools grimmory to a version beyond 3.3.3/3.4.1 to address the authorization bypass in the Download Endpoint. If updating is not possible, disable the affected component or restrict access to the KoboController.java file until a patch is applied.

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