OPEN-BRAIN <= 0.5.0 - Authenticated (Administrator+) Stored Cross-Site Scripting via 'API Key' Setting
Strategic Overview
- Status
- Unpatched
- Affected Plugin
- OPEN-BRAIN
- Affected Version
<= 0.5.0- CVSS
- 4.4Medium
- Weakness type
- CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
- CVE
CVE-2026-3995
At a glance
CVE-2026-3995 is a medium-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the OPEN-BRAIN WordPress plugin, affecting versions <= 0.5.0. It carries a CVSS score of 4.4 (reachable over the network). Exploitation requires an authenticated account at Administrator level or above. No fixed release has been reported yet; treat installations running this software as exposed. Disclosed April 2026, reported by Muhammad Nur Ibnu Hubab.
Vulnerability Overview
The OPEN-BRAIN plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'API Key' settings field in all versions up to, and including, 0.5.0. This is due to insufficient input sanitization and output escaping. The plugin uses sanitize_text_field() which strips HTML tags but does not encode double quotes or other HTML-special characters needed for safe attribute context output. The API key value is saved via update_option() and later output into an HTML input element's value attribute without esc_attr() escaping. This makes it possible for authenticated attackers, with Administrator-level access, to inject arbitrary web scripts via attribute breakout payloads (e.g., double quotes followed by event handlers) that execute whenever a user accesses the plugin settings page.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, and no interaction from a victim user.
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
OPEN-BRAIN <= 0.5.0 carries this weakness at sanitize_text_field(), and reaching it takes an account at Administrator level or above. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.
Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. No fixed build of this plugin is recorded for OPEN-BRAIN yet, so installs running <= 0.5.0 stay exposed until the vendor ships one.
Remediation
No known patch available. Please review the vulnerability's details in depth and employ mitigations based on your organization's risk tolerance. It may be best to uninstall the affected software and find a replacement.
How does WordSec protect against this?
An attacker needs Administrator access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. No patched version is recorded yet, which is the case where a filtering layer matters most, because there is nothing to update to.
- Firewall
- Alerts
External References
Related records
Other vulnerabilities in OPEN-BRAIN
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