CVE-2026-52819 kimai CVE debrief

Who should care

Defenders responsible for Kimai installations, particularly those with multiple team leads and users, should assess their exposure and verify access controls. They need to ensure that the access controls are in place and functioning correctly to prevent unauthorized access to sensitive timesheet data. Additionally, defenders should review the system logs to detect any potential exploitation of this vulnerability. Upgrading to version 2.57.0 or later is a 2

Why it matters

CVE-2026-52819 allows team leads to retrieve timesheets of other users without proper access control, potentially exposing sensitive data.

• Team leads may be able to access sensitive timesheet data of other users
• Defenders need to verify access controls and upgrade to version 2.57.0 or later
• Unusual activity monitoring is necessary to detect potential exploitation

Technical summary

The vulnerability is caused by the TimesheetController::cgetAction() method adding resolved users directly to the query without proper access control. This allows a team lead to retrieve timesheets of other users, including descriptions, timing data, tags, rate, and internal rate. The issue is fixed in version 2.57.0, where access control is enforced to prevent unauthorized access to timesheets. A team lead should not be able to access timesheets without proper authorization, but the current implementation fails to enforce this.

Defensive priority

Defenders should prioritize verifying their Kimai installation's access controls and upgrading to version 2.57.0 or later.

Recommended defensive actions

• Verify Kimai installation's access controls
• Upgrade to version 2.57.0 or later
• Monitor timesheet access for unusual activity
• Review compensating controls for exposed systems
• Check relevant monitoring, detection, and logs for exposed assets
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability is caused by the TimesheetController::cgetAction() method adding resolved users directly to the query without proper access control. This allows a team lead to retrieve timesheets of other users.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.