GHSA-R8VR-M544-QH4H
Vulnerability from github – Published: 2026-07-14 00:05 – Updated: 2026-07-14 00:05Summary
Kimai 2.56.0 contains authenticated cross-site request forgery issues in its timesheet state-changing API endpoints. The application reuses the browser's existing session for /api/* requests, and both the stop and restart operations are exposed through GET and PATCH routes that directly modify business state.
As a result, an attacker can trick a logged-in user into visiting a malicious page and cause unauthorized timesheet actions without the victim's consent. Depending on the endpoint, this can stop a running timesheet or create and start a new one from historical data.
Details
The issue affects at least the following API routes:
GET /api/timesheets/{id}/stopGET /api/timesheets/{id}/restart
Both routes are non-read-only operations but are still exposed as GET. In src/API/TimesheetController.php.
A PoC was provided, but removed for security reasons.
Impact
This 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's knowledge.
These 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.
Solution
The GET routes were removed, both stop and restart are only available via PATCH.
See https://www.kimai.org/en/security/ghsa-r8vr-m544-qh4h for more information.
{
"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"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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