AI Threat Alert
CVE-2026-9021
MEDIUMThe 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...
Full CISO analysis pending enrichment.
What systems are affected?
| Package | Ecosystem | Vulnerable Range | Patched |
|---|---|---|---|
| Easy Invoice – Invoice Generator, PDF Quotes & Payments | — | — | No patch |
Do you use Easy Invoice – Invoice Generator, PDF Quotes & Payments? You're affected.
How severe is it?
What is the attack surface?
What should I do?
No patch available
Monitor for updates. Consider compensating controls or temporary mitigations.
Which compliance frameworks are affected?
Compliance analysis pending. Sign in for full compliance mapping when available.
Frequently Asked Questions
What is CVE-2026-9021?
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.
Is CVE-2026-9021 actively exploited?
No confirmed active exploitation of CVE-2026-9021 has been reported, but organizations should still patch proactively.
How to fix CVE-2026-9021?
No patch is currently available. Monitor vendor advisories for updates.
What is the CVSS score for CVE-2026-9021?
CVE-2026-9021 has a CVSS v3.1 base score of 5.3 (MEDIUM).
What are the technical details?
Original Advisory
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.
Weaknesses (CWE)
CWE-862 — Missing Authorization: The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
- [Architecture and Design] Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- [Architecture and Design] Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
Source: MITRE CWE corpus.
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N References
- plugins.trac.wordpress.org/browser/easy-invoice/tags/2.1.12/includes/Controllers/QuoteController.php
- plugins.trac.wordpress.org/browser/easy-invoice/tags/2.1.12/includes/Controllers/QuoteController.php
- plugins.trac.wordpress.org/browser/easy-invoice/tags/2.1.12/includes/Controllers/QuoteController.php
- plugins.trac.wordpress.org/browser/easy-invoice/tags/2.1.12/templates/quotes/single.php
- plugins.trac.wordpress.org/browser/easy-invoice/tags/2.2.0/includes/Controllers/QuoteController.php
- plugins.trac.wordpress.org/browser/easy-invoice/tags/2.2.0/includes/Controllers/QuoteController.php
- plugins.trac.wordpress.org/browser/easy-invoice/tags/2.2.0/includes/Controllers/QuoteController.php
- plugins.trac.wordpress.org/browser/easy-invoice/tags/2.2.0/templates/quotes/single.php
- plugins.trac.wordpress.org/changeset/3517910/easy-invoice/trunk/includes/Controllers/QuoteController.php
- wordfence.com/threat-intel/vulnerabilities/id/dab1c93d-e83c-4d38-be80-56d8e32f1894