Kimai is an open-source time tracking application. In versions 2.52.0 and below, the User Preferences API endpoint (PATCH /api/users/{id}/preferences) applies submitted preference values without checking the isEnabled() flag on preference objects. Although the hourly_rate and internal_rate fields are correctly marked as disabled for users lacking the hourly-rate role permission, the API ignores this restriction and saves the values directly. Any authenticated user can modify their own billing rates through this endpoint, resulting in unauthorized financial tampering affecting invoices and timesheet calculations. This issue has been fixed in version 2.53.0.

Kimai is an open-source time tracking application. In versions 1.16.3 through 2.52.0, the escapeForHtml() function in KimaiEscape.js does not escape double quote or single quote characters. When a user's profile alias is inserted into an HTML attribute context via the team member form prototype and rendered through innerHTML, this incomplete escaping allows HTML attribute injection. An authenticated user with ROLE_USER privileges can store a malicious alias that executes JavaScript in the browser of any administrator viewing the team form, resulting in stored XSS with privilege escalation. This issue has been fixed in version 2.53.0.

Kimai is a web-based multi-user time-tracking application. Prior to version 2.51.0, "GET /api/invoices/{id}" only checks the role-based view_invoice permission but does not verify the requesting user has access to the invoice's customer. Any user with ROLE_TEAMLEAD (which grants view_invoice) can read all invoices in the system, including those belonging to customers assigned to other teams. This issue has been patched in version 2.51.0.

Kimai 2 contains a persistent cross-site scripting vulnerability that allows attackers to inject malicious scripts into timesheet descriptions. Attackers can insert SVG-based XSS payloads in the description field to execute arbitrary JavaScript when the page is loaded and viewed by other users.

Kimai is a web-based multi-user time-tracking application. Prior to version 2.46.0, Kimai's export functionality uses a Twig sandbox with an overly permissive security policy (`DefaultPolicy`) that allows arbitrary method calls on objects available in the template context. An authenticated user with export permissions can deploy a malicious Twig template that extracts sensitive information including environment variables, all user password hashes, serialized session tokens, and CSRF tokens. Version 2.46.0 patches this issue.