Vikunja is an open-source self-hosted task management platform. Prior to 2.4.0, POST /api/v1/projects/{project}/views/{view}/buckets/{bucket}/tasks accepts a body supplied task_id but TaskBucket.CanUpdate in pkg/models/kanban_task_bucket.go authorizes only the project, view, and bucket from the URL. updateTaskBucket then calls Task.ReadOne without a separate task permission check, returns the victim task contents, and can update the task done state when the attacker chooses a done bucket. Because task identifiers are global sequential values, an authenticated user can enumerate cross-tenant tasks and modify their completion metadata through both the v1 and v2 routes that share this model. This issue is fixed in version 2.4.0.

Project Subscriptions

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-5pg6-m483-7vrg Vikunja has cross-tenant IDOR in kanban move-task endpoint via unauthorized body task_id
Fixes

Solution

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Workaround

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History

Fri, 28 Aug 2026 19:45:00 +0000

Type Values Removed Values Added
Description Vikunja is an open-source self-hosted task management platform. Prior to 2.4.0, POST /api/v1/projects/{project}/views/{view}/buckets/{bucket}/tasks accepts a body supplied task_id but TaskBucket.CanUpdate in pkg/models/kanban_task_bucket.go authorizes only the project, view, and bucket from the URL. updateTaskBucket then calls Task.ReadOne without a separate task permission check, returns the victim task contents, and can update the task done state when the attacker chooses a done bucket. Because task identifiers are global sequential values, an authenticated user can enumerate cross-tenant tasks and modify their completion metadata through both the v1 and v2 routes that share this model. This issue is fixed in version 2.4.0.
Title Vikunja: Cross-tenant IDOR in kanban move-task endpoint via unauthorized body task_id
Weaknesses CWE-639
References
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-28T16:51:48.114Z

Reserved: 2026-06-16T14:33:35.710Z

Link: CVE-2026-55066

cve-icon Vulnrichment

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cve-icon NVD

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cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses