Invoice123 <= 1.7.0 - Missing Authorization to Authenticated (Subscriber+) Setting Modification via s123_submit_api_key & s123_submit_invoice_settings AJAX actions
Strategic Overview
- Status
- Patched in 1.7.1
- Affected Plugin
- Invoice123
- Affected Version
<= 1.7.0- CVSS
- 4.3Medium
- Weakness type
- CWE-862 · Missing Authorization
- CVE
CVE-2026-9857
At a glance
CVE-2026-9857 is a medium-severity Missing Authorization vulnerability in the Invoice123 WordPress plugin, affecting versions <= 1.7.0. It carries a CVSS score of 4.3 (reachable over the network; low attack complexity). Exploitation requires an authenticated account at Subscriber level or above. The issue is fixed in version 1.7.1; sites on affected versions should update now. Disclosed July 2026, reported by Benedictus Jovan (aillesiM).
Vulnerability Overview
The Invoice123 plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 1.7.0. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for authenticated attackers, with subscriber-level access and above, to overwrite the plugin's API key stored in wp_options, modify invoice plugin settings, and alter WooCommerce tax rate data in the wp_woocommerce_tax_rates table.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user.
CWE-862: Missing Authorization
Reaching this weakness in Invoice123 <= 1.7.0 takes an account at Subscriber level or above. A missing authorization check means a function is reachable by anyone who can reach the endpoint, because the code never asks whether the caller is allowed to perform the action.
Any user who can reach the endpoint gets to run an action reserved for higher-privileged roles, from reading protected data to changing settings or content. For Invoice123 the fix is 1.7.1: builds <= 1.7.0 are affected, anything from 1.7.1 onward is not.
Remediation
Update to version 1.7.1, or a newer patched version
How does WordSec protect against this?
Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Invoice123 1.7.1 closes this, and updating the plugin is the step that ends it.
- Login Security
- Alerts
External References
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