Kimai: Login CSRF in the Timesheet Stop and Restart API Endpoints Allows Unauthorized State Changes

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

5.3 · 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 · score source

EPSS

• CVE-2026-52823: 0.30% estimated exploitation activity in the next 30 days; percentile 22.53 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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}/stop - GET /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…

Published by the source

14 Jul 2026, 00:05 UTC

Last modified by the source

14 Jul 2026, 00:05 UTC

Source last checked

26 Oct 2026, 14:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-r8vr-m544-qh4h

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# Patch Next advisory brief: CVE-2026-52823

Advisory: Kimai: Login CSRF in the Timesheet Stop and Restart API Endpoints Allows Unauthorized State Changes
IDs: CVE-2026-52823, GHSA-r8vr-m544-qh4h
Record: https://patchnext.com/advisories/cve-2026-52823 (revision 1, source checked 26 Oct 2026, 14:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: kimai/kimai 2.58.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist kimai/kimai: affected <= 2.57.0; fixed in 2.58.0

## Suggested inspection (read-only)
- Packagist kimai/kimai: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on kimai/kimai.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-r8vr-m544-qh4h (GitHub-reviewed advisory GHSA-r8vr-m544-qh4h lists affected ranges: Packagist kimai/kimai >=0 <=2.57.0)

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