CVE-2026-8438: All-In-One Security (AIOS) <= 5.4.7 - Unauthenticated Stored Cross-Site Scripting via REST API Request Path
The All-In-One Security (AIOS) – Security and Firewall plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to and including 5.4.7. This is due to insufficient input sanitization in the getrestroute() function and missing output escaping in the columndefault() method of the debug log list table. When the 'Disable REST API for non-logged in users' feature (aiowpsdisallowunauthorizedrestrequests) is enabled alongside debug logging (aiowpsenabledebug), an unauthenticated attacker can embed arbitrary HTML or JavaScript in the REST request path. The path is retrieved via urldecode($SERVER['REQUESTURI']), which decodes URL-encoded payloads into literal HTML characters. This decoded, unsanitized value is concatenated directly into a debug log message and stored in the database. When an administrator navigates to the AIOS Dashboard Debug Logs page, the columndefault() method returns the raw database value without escaping, and the parent list table echoes it directly, causing JavaScript execution in the administrator's browser session. This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute when an administrator views the debug log page, enabling nonce theft, privileged AJAX/REST actions, and potential full site compromise.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Disable the 'Disable REST API for non-logged in users' feature (aiowps_disallow_unauthorized_rest_requests) if aiowps_enable_debug (debug logging) is enabled to prevent unauthenticated REST request paths from being stored and executed via the debug log.
All-In-One Security (AIOS) - Security and Firewall plugin for WordPress aiowps_disallow_unauthorized_rest_requests = disabled - Configuration
Disable debug logging (aiowps_enable_debug) to prevent decoded REST request paths from being concatenated into the debug log and stored unescaped in the database.
All-In-One Security (AIOS) - Security and Firewall plugin for WordPress aiowps_enable_debug = disabled
Event History
Frequently Asked Questions
What is the severity of CVE-2026-8438?
CVE-2026-8438 has a high severity rating of 7.2.
How does CVE-2026-8438 exploit work?
CVE-2026-8438 exploits the All-In-One Security plugin's insufficient input sanitization and missing output escaping, allowing unauthenticated stored cross-site scripting.
How can I mitigate CVE-2026-8438?
Mitigate CVE-2026-8438 by updating the All-In-One Security plugin to version 5.4.8 or later.
Who is affected by CVE-2026-8438?
Users of the All-In-One Security plugin for WordPress versions 5.4.7 and earlier are affected by CVE-2026-8438.
What type of vulnerability is CVE-2026-8438?
CVE-2026-8438 is classified as a Stored Cross-Site Scripting vulnerability.