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).

Severity (CVSS 4.0)5.3Medium
Exploit odds (30 days)0.3%top 80.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

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)

VendorProductVersions
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