{"id":"CVE-2026-91984","title":"Vikunja before 2.6.0 fails to validate that user-supplied project_view_id in task-position requests belongs to the task's project","summary":"Vikunja before 2.6.0 fails to validate that user-supplied project_view_id in task-position requests belongs to the task's project. Authenticated attackers can insert task position rows into arbitrary other tenant project views via POST o…","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N","cwe":["CWE-639","CWE-863"],"vendor":"go-vikunja","product":"vikunja","affected":["vikunja < 2.6.0"],"published":"2026-09-15","updated":"2026-09-17","sourceUpdated":"2026-09-17T20:18:54.770","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-91984","references":[{"url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-w39f-h553-h2mx","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/vikunja-before-2.6.0-broken-object-level-authorization-via-task-position","label":"disclosure@vulncheck.com"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-91984"},{"url":"https://github.com/go-vikunja/vikunja/pull/3688"},{"url":"https://github.com/go-vikunja/vikunja/commit/077dc4de79ce6f1ab59215a2c7bf9b30423685f2"},{"url":"https://github.com/go-vikunja/vikunja/releases/tag/v2.6.0"},{"url":"https://github.com/advisories/GHSA-w39f-h553-h2mx"},{"url":"https://github.com/go-vikunja/vikunja"}],"tags":["nvd","cve.org","ghsa","go","osv"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-17T19:16:26.702196Z"},"epss":0.00264,"epssPercentile":0.18232,"ingestedAt":"2026-09-15T15:39:12.909Z","aliases":["GHSA-w39f-h553-h2mx","GO-2026-6755"],"ecosystem":"go","patched":["code.vikunja.io/api 2.6.0"],"slug":"CVE-2026-91984","body":"## Overview\n\nVikunja before 2.6.0 fails to validate that user-supplied project_view_id in task-position requests belongs to the task's project. Authenticated attackers can insert task position rows into arbitrary other tenant project views via POST or PUT task-position endpoints.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-91984)\n\nAffected packages:\n\n- `code.vikunja.io/api <= 2.5.0`\n\nPatched in:\n\n- `code.vikunja.io/api 2.6.0`\n\nSource: https://github.com/advisories/GHSA-w39f-h553-h2mx","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":23.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}