Kimai: Timesheet PATCH/POST allows assigning to project outside user's team via query_builder OR-bypass

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:L/VI:L/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-52820: 0.45% estimated exploitation activity in the next 30 days; percentile 39.07 (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 The Timesheet API PATCH /api/timesheets/{id} and POST /api/timesheets endpoints accept a user-supplied project ID and resolve it through a Symfony EntityType whose querybuilder allows the submitted ID to satisfy the access predicate via an unconditional OR branch. As a result, any authenticated user can re-assign their own timesheet to any project in the database — including projects that belong to teams or customers they have no membership in and cannot otherwise see. The user can then read serialized project/customer details via GET /api/timesheets/{id}?full=true, leaking metadata (name, currency, customer hierarchy) that would otherwise be filtered out by the team ACL. Details Entry point — only ownership is checked in src/API/TimesheetController.php:317-355 src/Voter/TimesheetVoter.php:134-142: For an own-timesheet, only editowntimesheet is required. The voter does not look at the new project being submitted; it only validates the existing record's ownership. Form replays…

Published by the source

13 Jul 2026, 23:55 UTC

Last modified by the source

13 Jul 2026, 23:55 UTC

Source last checked

26 Oct 2026, 14:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-vrr2-g9gh-c3jc

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# Patch Next advisory brief: CVE-2026-52820

Advisory: Kimai: Timesheet PATCH/POST allows assigning to project outside user's team via query_builder OR-bypass
IDs: CVE-2026-52820, GHSA-vrr2-g9gh-c3jc
Record: https://patchnext.com/advisories/cve-2026-52820 (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 2.57.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist kimai/kimai: affected <= 2.56.0; fixed in 2.57.0

## 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-vrr2-g9gh-c3jc (GitHub-reviewed advisory GHSA-vrr2-g9gh-c3jc lists affected ranges: Packagist kimai/kimai >=0 <=2.56.0)

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