Vulnerability · Published Oct 28, 2026 · Assigned by GitHub_M
CVE-2026-55561InvoicePlane: Guest user IDOR in quote approval and rejection
Medium 5.3
In plain English
A medium-severity authorization bypass via user-controlled key in InvoicePlane from InvoicePlane. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities).
Official description
InvoicePlane is a self-hosted open source application for managing invoices, clients, and payments. Prior to 1.7.2-beta-1, guest users can approve or reject quotes belonging to any client, not just their assigned clients. The `approve()` and `reject()` methods in the Guest Quotes controller, `application/modules/guest/controllers/Quotes.php`, call `approve_quote_by_id($quote_id)` and `reject_quote_by_id($quote_id)` directly without the `where_in('ip_quotes.client_id', $this->user_clients)` scoping that sibling methods use. A guest user assigned to one client can change another client's quote status by supplying sequential integer `quote_id` values, and `email_quote_status()` also sends notification emails. Additionally, `generate_pdf()` calls `mark_viewed($quote_id)` before checking the client scope, allowing a guest user to mark another client's quote as viewed. These issues are fixed in version 1.7.2-beta-1 and the subsequent stable version 1.7.2.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| InvoicePlane | InvoicePlane | < 1.7.2-beta-1 |
Weakness: CWE-639 · Vector: 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
References
- https://github.com/InvoicePlane/InvoicePlane/security/advisories/GHSA-6xj3-274m-4mvg x_refsource_CONFIRM
- https://github.com/InvoicePlane/InvoicePlane/pull/1413 x_refsource_MISC
- https://github.com/InvoicePlane/InvoicePlane/pull/1471 x_refsource_MISC
- https://github.com/InvoicePlane/InvoicePlane/commit/424dc44eb54030b93176bb08cba07ba12d7ae451 x_refsource_MISC
- https://github.com/InvoicePlane/InvoicePlane/commit/fca7792a24de0a749d881cbbe4af6f58e9545d20 x_refsource_MISC
- https://github.com/InvoicePlane/InvoicePlane/releases/tag/v1.7.2 x_refsource_MISC
- https://github.com/InvoicePlane/InvoicePlane/releases/tag/v1.7.2-beta-1 x_refsource_MISC