{"id":"CVE-2026-123503","kind":"vulnerability","aliases":["CVE-2026-123503"],"related":[],"title":"Vikunja: users with project write access can delete buckets they should not","description":"Vikunja before 2.7.1 contains an improper authorization vulnerability in canDoBucket that allows users with project write access to delete buckets via a mismatched view ID. Attackers can request deletion through another view's bucket endpoint to bypass the last-bucket rule, leaving dangling default/done bucket references and inconsistent task buckets.","summary":"Vikunja, a self-hosted task manager, checks bucket permissions against the wrong view, so a user with write access to a project can delete a bucket through another view's endpoint. This bypasses the rule that a project must keep at least one bucket and leaves task buckets and default/done references inconsistent.","severity":"medium","cvss":5.4,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["package","project-management","self-hosted","vikunja"],"not_affected_if":["managed-hosting","read-only-projects","single-user"],"how_to_check":"- Check the installed Vikunja version, for example with `vikunja version` or the image tag, and compare it with the fixed version below.\n- Confirm whether untrusted or non-admin users have write access to shared projects.","fix":"- Vikunja: move to `2.7.1` or later (the description says before 2.7.1 is affected).","status":"open","published_at":"2026-11-08T02:16:38+00:00","first_seen_at":"2026-11-08T02:21:08+00:00","triaged_at":"2026-11-08T02:25:16+00:00","updated_at":"2026-11-08T02:25:16+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-11-08T02:25:16Z","model":"claude-haiku-5-5","output":{"fix":"- Vikunja: move to `2.7.1` or later (the description says before 2.7.1 is affected).","reach":"network","title":"Vikunja: users with project write access can delete buckets they should not","impact":"low","summary":"Vikunja, a self-hosted task manager, checks bucket permissions against the wrong view, so a user with write access to a project can delete a bucket through another view's endpoint. This bypasses the rule that a project must keep at least one bucket and leaves task buckets and default/done references inconsistent.","audience":"businesses","category":"package","nicknames":[],"who_cares":["vikunja","self-hosted","project-management"],"confidence":0.7,"fix_status":"available","needs_auth":"yes","worst_case":"Authenticated project members delete buckets, corrupting task board state.","analyst_note":"","how_to_check":"- Check the installed Vikunja version, for example with `vikunja version` or the image tag, and compare it with the fixed version below.\n- Confirm whether untrusted or non-admin users have write access to shared projects.","plain_action":"","needs_analyst":false,"not_affected_if":["single-user","read-only-projects","managed-hosting"],"who_is_affected":"Teams that run a self-hosted Vikunja instance where several users have write access to shared projects. A single-user instance or one where only trusted people can write to projects is less exposed. The sources do not describe exposure on hosted Vikunja.","user_interaction":"no","needs_special_setup":"no","severity_if_unknown":"unknown"},"cost_usd":0.000691,"input_tokens":4281,"output_tokens":526,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-123503':12A,15A '-2026':11A,14A '2.7.1':79C 'access':6A,43B,93C 'allow':88C 'anoth':52B,107C 'attack':102C 'author':83C 'bucket':9A,32B,50B,68B,72B,96C,110C,117C,122C,127C 'bypass':57B,113C 'candobucket':86C 'check':31B 'contain':80C 'cve':10A,13A 'dangl':120C 'default/done':74B,121C 'delet':8A,48B,95C,105C 'endpoint':55B,111C 'host':22B,28B 'id':101C 'improp':82C 'inconsist':76B,125C 'keep':64B 'last':116C 'last-bucket':115C 'least':66B 'leav':70B,119C 'manag':19B,30B 'mismatch':99C 'must':63B 'one':67B 'packag':16B 'permiss':33B 'project':4A,18B,46B,62B,91C 'project-manag':17B 'refer':75B,123C 'request':104C 'rule':59B,118C 'self':21B,27B 'self-host':20B,26B 'task':29B,71B,126C 'user':2A,40B,89C 'via':97C 'view':37B,53B,100C,108C 'vikunja':1A,23B,24B,77C 'vulner':84C 'write':5A,42B,92C 'wrong':36B","nicknames":[],"mitigations":[],"who_affected":"Teams that run a self-hosted Vikunja instance where several users have write access to shared projects. A single-user instance or one where only trusted people can write to projects is less exposed. The sources do not describe exposure on hosted Vikunja.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"pkeys":[],"ptokens":[],"labels":["medium","package","projectmanagement","selfhosted","vikunja"],"campaign_type":null,"search_a":"'-123503':12A,15A '-2026':11A,14A 'access':6A 'bucket':9A 'cve':10A,13A 'delet':8A 'project':4A 'user':2A 'vikunja':1A 'write':5A","search_b":"'access':43B 'anoth':52B 'bucket':32B,50B,68B,72B 'bypass':57B 'check':31B 'default/done':74B 'delet':48B 'endpoint':55B 'host':22B,28B 'inconsist':76B 'keep':64B 'least':66B 'leav':70B 'manag':19B,30B 'must':63B 'one':67B 'packag':16B 'permiss':33B 'project':18B,46B,62B 'project-manag':17B 'refer':75B 'rule':59B 'self':21B,27B 'self-host':20B,26B 'task':29B,71B 'user':40B 'view':37B,53B 'vikunja':23B,24B 'write':42B 'wrong':36B","search_c":"'2.7.1':79C 'access':93C 'allow':88C 'anoth':107C 'attack':102C 'author':83C 'bucket':96C,110C,117C,122C,127C 'bypass':113C 'candobucket':86C 'contain':80C 'dangl':120C 'default/done':121C 'delet':95C,105C 'endpoint':111C 'id':101C 'improp':82C 'inconsist':125C 'last':116C 'last-bucket':115C 'leav':119C 'mismatch':99C 'project':91C 'refer':123C 'request':104C 'rule':118C 'task':126C 'user':89C 'via':97C 'view':100C,108C 'vikunja':77C 'vulner':84C 'write':92C","first_public_at":"2026-10-22T10:01:58+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-123503","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123503","severity":null,"published_at":"2026-11-08T02:16:38+00:00","modified_at":"2026-11-08T02:16:38+00:00","first_seen_at":"2026-11-08T02:21:08+00:00","fetched_at":"2026-11-08T02:21:08+00:00","note":null}],"documents":[{"id":99155,"url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-9xh7-5jg8-mf43","title":"Vendor advisory: github.com","kind":"vendor","source":"nvd","publisher":"vendor","text":null,"published_at":"2026-10-22T10:01:58+00:00","relation":"advisory","confidence":null,"note":"Vendor advisory: github.com"},{"id":99156,"url":"https://www.vulncheck.com/advisories/vikunja-before-2.7.1-improper-authorization-in-kanban-bucket-deletion","title":"Third-party advisory: www.vulncheck.com","kind":"advisory","source":"nvd","publisher":"research","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Third-party advisory: www.vulncheck.com"}],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}