Cross-tenant position writes via unchecked view ownership
Published Sep 15, 2026 · Updated Sep 15, 2026
Improper authorization in Vikunja before 2.6.0 allows remote authenticated users to write task positions into other tenants' views. In affected builds, the task-position handler accepts a supplied project_view_id and upserts a task_positions row without confirming that the view belongs to the task's project. Any authenticated account able to update a task can therefore alter ordering data in an arbitrary tenant project view.
Summary
What happened
Improper authorization in Vikunja before 2.6.0 allows remote authenticated users to write task positions into other tenants' views. In affected builds, the task-position handler accepts a supplied project_view_id and upserts a task_positions row without confirming that the view belongs to the task's project. Any authenticated account able to update a task can therefore alter ordering data in an arbitrary tenant project view.
The record
- CVE
- CVE-2026-91984
- Published
- Sep 15, 2026
- Updated
- Sep 15, 2026
- Vendor
- Vikunja
- Product
- Vikunja
- Classifications
- T1565.001
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 15, 2026CVE publishedPublication date reported by the CVE source.
- Sep 15, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <2.6.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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