Authenticated cross-tenant defacement via bucket mass assignment
Published Aug 28, 2026 · Updated Aug 28, 2026
Authorization bypass in Vikunja before 2.4.0 allows remote authenticated users to deface another tenant's Kanban view. Bucket.Update in pkg/models/kanban.go mass-assigns the request body's project_view_id after checking only the URL-selected source project and view. Any signed-in user can move an attacker-owned, attacker-titled bucket into an enumerated destination view, while existing victim content remains unchanged.
Summary
What happened
Authorization bypass in Vikunja before 2.4.0 allows remote authenticated users to deface another tenant's Kanban view. Bucket.Update in pkg/models/kanban.go mass-assigns the request body's project_view_id after checking only the URL-selected source project and view. Any signed-in user can move an attacker-owned, attacker-titled bucket into an enumerated destination view, while existing victim content remains unchanged.
The record
- CVE
- CVE-2026-55067
- Published
- Aug 28, 2026
- Updated
- Aug 28, 2026
- Vendor
- Vikunja
- Product
- Vikunja
- Classifications
- CWE-639, T1565.001
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 28, 2026CVE publishedPublication date reported by the CVE source.
- Aug 28, 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=< 2.4.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA-569v-q83c-3j3g proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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