CVE-2026-111920
Received Received - Intake

Broken Access Control in Vikunja 2.6.0

Publication date: 2026-10-17

Last updated on: 2026-10-17

Assigner: VulnCheck

Description
Vikunja 2.6.0 contains a broken access control flaw in getProjectAccessForUser (pkg/models/project_access.go), which resolves a user's effective project permission as the maximum over the project tree, silently overriding explicit lower-permission shares on sub-projects. A collaborator with write access on a parent project but read-only access to a child project can modify the child project's tasks and content.

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Meta Information

Published
2026-10-17
Last Modified
2026-10-17
Generated
2026-10-17
AI Q&A
2026-10-17
EPSS Evaluated
N/A
NVD
CVE-2026-111920
EUVD
EUVD-2026-103288

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
go-vikunja vikunja 2.6.0

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-269 The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.

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Executive Summary

CVE-2026-111920 is a broken access control flaw in Vikunja 2.6.0 where the system incorrectly resolves a user's effective project permissions. Instead of honoring explicit lower permissions on child projects, it overrides them with higher inherited permissions from parent projects using a MAX aggregation in recursive queries. This allows users with higher parent permissions to bypass intended restrictions on sub-projects.

Detection Guidance

Check Vikunja version with: curl -s http://your-vikunja-server/info | grep version. If running 2.6.0, the system is vulnerable. Review project permissions for users with higher parent project access but restricted child project access to identify unauthorized modifications.

Impact Analysis

A collaborator with write access on a parent project but read-only access to a child project can modify tasks, delete content, or re-share sensitive sub-projects despite explicit restrictions. This could lead to unauthorized data changes or exposure of confidential information within restricted child projects.

Compliance Impact

This vulnerability could lead to unauthorized modifications or deletions of sensitive data in sub-projects, potentially violating data integrity and access control requirements under GDPR and HIPAA. If a user with higher parent project permissions bypasses child project restrictions, it may result in unauthorized access to personal or protected health information.

Mitigation Strategies

Downgrade to Vikunja v2.5.0 or earlier where the permission system worked correctly. If downgrading is not possible, restrict project access manually by auditing all project hierarchies and removing inherited permissions that override explicit child restrictions.

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