CVE-2026-93955
MediumCVSS 4.3Summary
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.
Risk Assessment
An attacker can access unauthorized resources, potentially leading to data leakage.
Recommendation
Update grimmory to a version later than 3.4.1. Monitor access to the Download endpoint.
Other vulnerabilities in grimmory
See all- CVE-2026-93954Medium
A security vulnerability has been detected in grimmory-tools grimmory up to 3.3.3/3.4.1. Affected is the function AppSettingController.getAppSettings of the file backend/src/main/java/org/booklore/controller/AppSettingController.java of the component Settings API Endpoint. Such manipulation leads to incorrect authorization. The attack can be launched remotely. The exploit has been disclosed publicly and may be used. The name of the patch is 2b66ca6df8110f6b512e030b54c16b9fbe318f17. Applying a patch is advised to resolve this issue.
- CVE-2026-42451Medium
Grimmory, a self-hosted digital library, prior to version 2.3.1 contains a stored cross-site scripting (XSS) vulnerability in its browser-based EPUB reader. This allows an attacker to embed arbitrary JavaScript in a crafted EPUB file. When a victim opens the book, the script executes in their browser with full access to the Grimmory application's session context. This can enable session token theft and account takeover, including administrative access if an administrator opens the affected book. This issue has been patched in version 2.3.1.
Original NVD description (English source)
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.