{"schemaVersion":3,"id":"CVE-2026-55064","aliases":["GHSA-44v6-7fxq-vgf4","GO-2026-6306"],"status":"published","duplicateOf":null,"title":"Vikunja incomplete fix for CVE-2026-35595: Write-only user can detach shared project from parent hierarchy via parent_project_id=0","description":"Vikunja is an open-source self-hosted task management platform. From 2.3.0 until 2.4.0, a user with Write but not Admin permission on a shared child project can detach it from its parent hierarchy by submitting parent_project_id equal to 0 to POST /api/v1/projects/{project}. The Project.CanUpdate authorization check in pkg/models/project_permissions.go and UpdateProject logic in pkg/models/project.go only gate nonzero parent values, while UpdateProject always persists parent_project_id, so the explicit zero value bypasses the Admin requirement introduced for CVE-2026-35595. Detachment severs the recursive permission-inheritance chain and can disrupt the owner’s hierarchy and inherited collaborator access. This issue is fixed in version 2.4.0.","dates":{"published":"2026-08-28T16:38:38.293Z","modified":"2026-08-28T20:29:30.143Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":4.3,"severity":"medium","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":4.3,"severity":"medium","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"OSV · 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recorded)","eol":null,"hubHref":null}],"affectedCount":2,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-44v6-7fxq-vgf4","label":"github.com/go-vikunja/vikunja/security/advisories/GHSA-44v6-7fxq-vgf4","hostname":"github.com","tags":["X Refsource CONFIRM","WEB","Advisory"]},{"url":"https://github.com/go-vikunja/vikunja/pull/3239","label":"github.com/go-vikunja/vikunja/pull/3239","hostname":"github.com","tags":["X Refsource MISC"]},{"url":"https://github.com/go-vikunja/vikunja/commit/781ffac198548ae4f3d1febc613caed8e0e11d01","label":"github.com/go-vikunja/vikunja/commit/781ffac198548ae4f3d1febc613caed8e0e11d01","hostname":"github.com","tags":["X Refsource MISC"]},{"url":"https://github.com/go-vikunja/vikunja/releases/tag/v2.4.0","label":"github.com/go-vikunja/vikunja/releases/tag/v2.4.0","hostname":"github.com","tags":["X Refsource MISC"]},{"url":"https://github.com/go-vikunja/vikunja","label":"github.com/go-vikunja/vikunja","hostname":"github.com","tags":["PACKAGE"]}],"lineage":{"upstream":[],"downstream":["OPENSUSE-SU-2026:21812-1","SUSE-SU-2026:23692-1","SUSE-SU-2026:23712-1"],"duplicates":[],"related":["OPENSUSE-SU-2026:21812-1","SUSE-SU-2026:23692-1","SUSE-SU-2026:23712-1"]},"timeline":[{"kind":"published","date":"2026-08-28T16:38:38.293Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-08-28T20:29:30.143Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":17,"level":"low","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-22T19:23:51.566Z","stale":false,"partial":false}}