{"cve":"CVE-2026-55066","nvd":{"published":"2026-08-28T20:18:23.897","modified":"2026-09-09T21:09:13.080","status":"Deferred","description":"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.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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","score":7.1},"cwes":["CWE-639"],"references":["https://github.com/go-vikunja/vikunja/commit/36cdc2ce2be0b8ccc74227d178b92047d59cd65f","https://github.com/go-vikunja/vikunja/pull/3239","https://github.com/go-vikunja/vikunja/releases/tag/v2.4.0","https://github.com/go-vikunja/vikunja/security/advisories/GHSA-5pg6-m483-7vrg"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:50:50.842544443+00:00"},"epss":{"cve":"CVE-2026-55066","score":0.00369,"percentile":0.30771,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-5pg6-m483-7vrg","url":"https://osv.dev/vulnerability/GHSA-5pg6-m483-7vrg","summary":"Vikunja has cross-tenant IDOR in kanban move-task endpoint via unauthorized body task_id","modified":"2026-09-02T19:41:30.652606332Z","packages":[{"ecosystem":"Go","name":"code.vikunja.io/api","purl":"pkg:golang/code.vikunja.io/api","ranges":["<2.4.0"],"fixed":["2.4.0"]}]},{"id":"GO-2026-6308","url":"https://osv.dev/vulnerability/GO-2026-6308","summary":"Vikunja has cross-tenant IDOR in kanban move-task endpoint via unauthorized body task_id in code.vikunja.io/api","modified":"2026-09-02T19:30:09.168752976Z","packages":[{"ecosystem":"Go","name":"code.vikunja.io/api","purl":"pkg:golang/code.vikunja.io/api","ranges":["all versions"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}