5.3
MEDIUM CVSS 3.1
CVE-2026-9021
Easy Invoice <= 2.1.19 - Unauthenticated Arbitrary Quote Accept/Decline and Invoice Creation via easy_invoice_accept_quote / easy_invoice_decline_quote AJAX Actions
Description

The Easy Invoice plugin for WordPress is vulnerable to Missing Authorization in versions up to, and including, 2.1.19. This is due to the plugin registering the easy_invoice_accept_quote and easy_invoice_decline_quote AJAX actions via wp_ajax_nopriv_ hooks and relying solely on a quote-scoped nonce that is rendered into the publicly accessible single quote template, combined with an ownership check that is gated behind an off-by-default Pro option (easy_invoice_pro_restrict_quote_to_client). This makes it possible for unauthenticated attackers to accept or decline arbitrary published quotes — and, depending on the configured accept action, automatically convert them into invoices (and even email them to the client) — by harvesting the per-quote nonce from the public quote page and submitting it to admin-ajax.

INFO

Published Date :

July 9, 2026, 11:16 a.m.

Last Modified :

July 9, 2026, 11:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-9021 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM [email protected]
Solution
Update the Easy Invoice plugin to a version that addresses the authorization flaw.
  • Update the Easy Invoice plugin immediately.
  • Ensure the Pro option to restrict quotes is enabled.
  • Review plugin settings for secure configurations.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-9021 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-9021 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-9021 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-9021 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Jul. 09, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'matrixaddons', 'product': 'Easy Invoice – Invoice Generator, PDF Quotes & Payments', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '2.2.19'}], 'defaultStatus': 'unaffected'}]
    Added Description The Easy Invoice plugin for WordPress is vulnerable to Missing Authorization in versions up to, and including, 2.1.19. This is due to the plugin registering the easy_invoice_accept_quote and easy_invoice_decline_quote AJAX actions via wp_ajax_nopriv_ hooks and relying solely on a quote-scoped nonce that is rendered into the publicly accessible single quote template, combined with an ownership check that is gated behind an off-by-default Pro option (easy_invoice_pro_restrict_quote_to_client). This makes it possible for unauthenticated attackers to accept or decline arbitrary published quotes — and, depending on the configured accept action, automatically convert them into invoices (and even email them to the client) — by harvesting the per-quote nonce from the public quote page and submitting it to admin-ajax.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
    Added CWE CWE-862
    Added Reference https://plugins.trac.wordpress.org/browser/easy-invoice/tags/2.1.12/includes/Controllers/QuoteController.php#L1022
    Added Reference https://plugins.trac.wordpress.org/browser/easy-invoice/tags/2.1.12/includes/Controllers/QuoteController.php#L1453
    Added Reference https://plugins.trac.wordpress.org/browser/easy-invoice/tags/2.1.12/includes/Controllers/QuoteController.php#L88
    Added Reference https://plugins.trac.wordpress.org/browser/easy-invoice/tags/2.1.12/templates/quotes/single.php#L1462
    Added Reference https://plugins.trac.wordpress.org/browser/easy-invoice/tags/2.2.0/includes/Controllers/QuoteController.php#L1022
    Added Reference https://plugins.trac.wordpress.org/browser/easy-invoice/tags/2.2.0/includes/Controllers/QuoteController.php#L1453
    Added Reference https://plugins.trac.wordpress.org/browser/easy-invoice/tags/2.2.0/includes/Controllers/QuoteController.php#L88
    Added Reference https://plugins.trac.wordpress.org/browser/easy-invoice/tags/2.2.0/templates/quotes/single.php#L1462
    Added Reference https://plugins.trac.wordpress.org/changeset/3517910/easy-invoice/trunk/includes/Controllers/QuoteController.php
    Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/dab1c93d-e83c-4d38-be80-56d8e32f1894?source=cve
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.