Solution

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.57.0"
      },
      "package": {
        "ecosystem": "Packagist",
        "name": "kimai/kimai"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.58.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-52822"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-285",
      "CWE-862"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-14T00:04:26Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nKimai 2.56.0 contains an authenticated authorization bypass in the timesheet `restart` and `duplicate` workflows. After a user loses access to a project, the user can still derive a new timesheet from one of their historical entries and create a new record under that now-unauthorized project and activity combination.\n\nThis is a permission revocation bypass with persistent write impact. The issue affects both `restart` and `duplicate`, which trust ownership of an old timesheet more than the user\u0027s current access to the underlying project, activity, and customer.\n\n### Details\n\nThe issue affects the following operations:\n\n- `PATCH /api/timesheets/{id}/restart`\n- `PATCH /api/timesheets/{id}/duplicate`\n\nThe root cause is that authorization gives too much weight to the fact that the original timesheet belongs to the current user. In `src/Voter/TimesheetVoter.php`, the `*_own_timesheet` branch is evaluated before team-based access checks.\n\nThe restart/duplicate capability check also verifies only object visibility, not whether the current user still has team-based access to the referenced objects. \n\nIn `src/API/TimesheetController.php`, the restart flow copies the historical `project` and `activity` into a new candidate timesheet.\n\nThe duplicate flow similarly clones the historical record and saves it.\n\nIn `src/Timesheet/TimesheetService.php`, creation of a new running entry still relies on `isGranted(\u0027start\u0027, $timesheet)`.\n\nFor historical entries that belong to the current user, this logic can still succeed through the `*_own_timesheet` branch even after project access has been revoked. As a result, normal creation pages correctly stop offering the revoked project, but `restart` and `duplicate` can still create new records under it.\n\nThe same weakness also affects the Web duplicate flow because the UI path ultimately calls the same save logic in `src/Controller/TimesheetAbstractController.php`:\n\n*A PoC was provided, but removed for security reasons.*\n\n### Impact\n\nThis vulnerability allows a user to keep writing new time entries into a project after project access has been revoked. That undermines administrative access-control changes and can pollute project time tracking, budget calculations, statistics, reports, and invoicing workflows.\n\nBecause both `restart` and `duplicate` can reuse historical project/activity bindings, old timesheet records effectively become reusable capability tokens that survive later access-control changes. This is not a UI artifact or a caching problem: new database rows are persisted after revocation.\n\n# Solution\n\nThe metoid `TimesheetVoter::canStart()` now checks team access for project and activity. This verification is used for new timesheets and also for the `duplication` and `restart` workflows.\n\nSee [https://www.kimai.org/en/security/ghsa-c6w6-57jj-62vh](https://www.kimai.org/en/security/ghsa-c6w6-57jj-62vh) for more information.",
  "id": "GHSA-c6w6-57jj-62vh",
  "modified": "2026-07-14T00:04:26Z",
  "published": "2026-07-14T00:04:26Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/kimai/kimai/security/advisories/GHSA-c6w6-57jj-62vh"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/kimai/kimai"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Improper Authorization in Kimai Timesheet Restart and Duplicate Allows New Timesheets After Project Access Revocation"
}