{"id":"CVE-2026-55066","title":"Vikunja is an open-source self-hosted task management platform","summary":"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…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","cwe":["CWE-639"],"vendor":"api","product":"code.vikunja.io/api","affected":["code.vikunja.io/api <= 2.3.0"],"patched":["code.vikunja.io/api 2.4.0"],"published":"2026-08-28","updated":"2026-09-09","sourceUpdated":"2026-09-09T21:09:13.080","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55066","references":[{"url":"https://github.com/go-vikunja/vikunja/commit/36cdc2ce2be0b8ccc74227d178b92047d59cd65f","label":"security-advisories@github.com"},{"url":"https://github.com/go-vikunja/vikunja/pull/3239","label":"security-advisories@github.com"},{"url":"https://github.com/go-vikunja/vikunja/releases/tag/v2.4.0","label":"security-advisories@github.com"},{"url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-5pg6-m483-7vrg","label":"security-advisories@github.com"},{"url":"https://github.com/advisories/GHSA-5pg6-m483-7vrg"}],"tags":["nvd","ghsa","go"],"epss":0.0027,"epssPercentile":0.19486,"aliases":["GHSA-5pg6-m483-7vrg"],"ecosystem":"go","ingestedAt":"2026-08-28T17:22:56.443Z","slug":"CVE-2026-55066","body":"## Overview\n\nVikunja 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-55066)\n\nAffected packages:\n\n- `code.vikunja.io/api <= 2.3.0`\n\nPatched in:\n\n- `code.vikunja.io/api 2.4.0`\n\nSource: https://github.com/advisories/GHSA-5pg6-m483-7vrg","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}