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CVE-2026-93955: Authorization Bypass in grimmory-tools grimmory

0
Medium
VulnerabilityCVE-2026-93955cvecve-2026-93955
Published: 09/19/2026 (09/19/2026, 22:15:09 UTC)
Source: CVE Database V5
Vendor/Project: grimmory-tools
Product: grimmory

Description

CVE-2026-93955 is an authorization bypass vulnerability in grimmory-tools grimmory affecting versions 3.3.0 through 3.4.1. The flaw exists in the streamFileToResponse function of the Download Endpoint, where manipulation of the bookId argument allows unauthorized access. The vulnerability can be exploited remotely. Although the issue has been publicly reported and exploit code is available, no official fix or patch has been identified.

CVSS v4.0

Score 5.3medium

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
Low
User Interaction
None
Vuln. Confidentiality
Low
Vuln. Integrity
None
Vuln. Availability
None
Subsq. Confidentiality
None
Subsq. Integrity
None
Subsq. Availability
None
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P

Affected software

grimmory-tools

grimmory

Affected versions
=3.3.0=3.3.1=3.3.2=3.3.3=3.4.0=3.4.1
GitHub Actionsmore threats →ai
grimmory-tools/grimmory
pkg:github/grimmory-tools/grimmory
Affected versions
=3.3.0=3.3.1=3.3.2=3.3.3=3.4.0=3.4.1
CPE configurations
cpe:2.3:a:grimmory-tools:grimmory:*:*:*:*:*:*:*:*

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AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 09/19/2026, 22:46:30 UTC

Technical Analysis

This vulnerability in grimmory-tools grimmory up to versions 3.3.3 and 3.4.1 involves an authorization bypass in the streamFileToResponse function within backend/src/main/java/org/booklore/controller/KoboController.java. By manipulating the bookId parameter, an attacker can bypass authorization controls and access resources without proper permissions. The issue is remotely exploitable. Despite public disclosure and available exploit code, no fixing commit or pull request has been found, and the related issue #2431 was closed without resolution.

Potential Impact

An attacker can remotely bypass authorization checks by manipulating the bookId argument in the Download Endpoint, potentially accessing protected resources without permission. This could lead to unauthorized data access. The CVSS 4.0 score is 5.3 (medium severity), indicating a moderate impact with no required privileges and no user interaction needed.

Mitigation Recommendations

No official fix or patch is currently available for this vulnerability. Users should monitor the vendor's communications for updates. Until a patch is released, consider implementing additional access controls or input validation on the bookId parameter if possible to mitigate unauthorized access.

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Technical Details

Data Version
5.2
Assigner Short Name
VulDB
Date Reserved
2026-09-19T08:51:16.505Z
Cvss Version
4.0
State
PUBLISHED

Threat ID: 6aaf0d7a55bf5e2cf50cd7d0

Added to database: 09/19/2026, 22:32:26 UTC

Last enriched: 09/19/2026, 22:46:30 UTC

Last updated: 09/19/2026, 23:25:33 UTC

Views: 7

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