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-2026-52823"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-352"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-14T00:05:04Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nKimai 2.56.0 contains authenticated cross-site request forgery issues in its timesheet state-changing API endpoints. The application reuses the browser\u0027s existing session for `/api/*` requests, and both the `stop` and `restart` operations are exposed through `GET` and `PATCH` routes that directly modify business state.\n\nAs a result, an attacker can trick a logged-in user into visiting a malicious page and cause unauthorized timesheet actions without the victim\u0027s consent. Depending on the endpoint, this can stop a running timesheet or create and start a new one from historical data.\n\n### Details\n\nThe issue affects at least the following API routes:\n\n- `GET /api/timesheets/{id}/stop`\n- `GET /api/timesheets/{id}/restart`\n\nBoth routes are non-read-only operations but are still exposed as `GET`. In `src/API/TimesheetController.php`.\n\n*A PoC was provided, but removed for security reasons.*\n\n### Impact\n\nThis vulnerability allows an attacker to trigger unauthorized business-state changes as a logged-in victim. In the validated `stop` case, a running timesheet can be stopped, affecting time tracking integrity and potentially availability of ongoing work tracking. In the `restart` case, a historical timesheet can be restarted and a new record can be created without the victim\u0027s knowledge.\n\nThese actions can corrupt time records, distort billing and reporting, interfere with approvals or audits, and create persistent database-side side effects. Because exploitation requires only that the victim visit a malicious page while authenticated, the attack barrier is low.\n\n# Solution\n\nThe `GET` routes were removed, both `stop` and `restart` are only available via `PATCH`.\n\nSee [https://www.kimai.org/en/security/ghsa-r8vr-m544-qh4h](https://www.kimai.org/en/security/ghsa-r8vr-m544-qh4h) for more information.",
  "id": "GHSA-r8vr-m544-qh4h",
  "modified": "2026-07-14T00:05:04Z",
  "published": "2026-07-14T00:05:04Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/kimai/kimai/security/advisories/GHSA-r8vr-m544-qh4h"
    },
    {
      "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": "Kimai: Login CSRF in the Timesheet Stop and Restart API Endpoints Allows Unauthorized State Changes"
}