---
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
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
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-17T19:16:26.702196Z'
epss: 0.00264
epssPercentile: 0.16443
ingestedAt: '2026-09-15T15:39:12.909Z'
---

## Overview

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 or PUT task-position endpoints.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.