CVE-2026-22428: Tooth Fairy Theme File Inclusion Flaw

CVE-2026-22428 Overview

CVE-2026-22428 is a PHP Local File Inclusion (LFI) vulnerability affecting the Tooth Fairy WordPress theme developed by AncoraThemes. The vulnerability stems from improper control of filename parameters used in PHP include/require statements, allowing attackers to include arbitrary local files from the server's filesystem.

This vulnerability is classified under CWE-98 (Improper Control of Filename for Include/Require Statement in PHP Program), which describes scenarios where user-controlled input is insufficiently validated before being used in file inclusion operations. Successful exploitation could allow attackers to read sensitive configuration files, access credentials, or potentially achieve code execution if combined with other attack vectors such as log poisoning.

Critical Impact

Attackers can leverage this Local File Inclusion vulnerability to read sensitive server files, potentially exposing database credentials, API keys, and other confidential information stored on WordPress installations using the Tooth Fairy theme.

Affected Products

• AncoraThemes Tooth Fairy WordPress Theme versions through 1.16
• WordPress installations using the vulnerable Tooth Fairy theme
• Web servers hosting affected WordPress sites

Discovery Timeline

• 2026-03-05 - CVE-2026-22428 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2026-22428

Vulnerability Analysis

The vulnerability exists due to improper input validation in the Tooth Fairy WordPress theme's PHP code. When the theme processes user-supplied input for file inclusion operations, it fails to adequately sanitize or restrict the filename parameter. This allows an attacker to manipulate the input to traverse directories and include arbitrary files from the local filesystem.

Local File Inclusion vulnerabilities in WordPress themes are particularly dangerous because WordPress installations typically contain sensitive files such as wp-config.php, which stores database credentials, authentication keys, and other critical configuration data. An attacker exploiting this vulnerability could potentially extract these credentials and gain unauthorized access to the underlying database or escalate their attack further.

Root Cause

The root cause of this vulnerability is insufficient input validation and sanitization in PHP include or require statements within the Tooth Fairy theme. The theme accepts user-controllable input that is subsequently used to construct file paths without proper filtering of directory traversal sequences (such as ../) or validation against an allowlist of permitted files.

This is a common pattern in vulnerable PHP applications where developers dynamically include files based on user input without implementing adequate security controls. The lack of proper path canonicalization and restriction allows attackers to escape the intended directory structure and access files outside the web application's scope.

Attack Vector

The attack vector for this vulnerability involves submitting malicious input through theme parameters that control file inclusion behavior. An attacker would craft a request containing directory traversal sequences to navigate from the theme's directory to sensitive files elsewhere on the server.

A typical exploitation scenario might involve manipulating a template or component parameter to include files such as /etc/passwd for information gathering or wp-config.php to extract database credentials. The attacker could leverage PHP wrapper protocols or null byte injection techniques depending on the PHP configuration and version.

The vulnerability requires network access to the target WordPress site but does not necessarily require authentication, depending on how the vulnerable functionality is exposed within the theme. For additional technical details, see the Patchstack vulnerability database entry.

Detection Methods for CVE-2026-22428

Indicators of Compromise

• Unusual HTTP requests containing directory traversal patterns such as ../ or encoded variants targeting theme endpoints
• Access logs showing requests for sensitive file paths like /etc/passwd, wp-config.php, or .htaccess through theme parameters
• Error logs indicating failed file inclusion attempts or unexpected file access patterns
• Web Application Firewall (WAF) alerts for LFI attack signatures targeting the Tooth Fairy theme

Detection Strategies

• Configure Web Application Firewall rules to detect and block requests containing directory traversal sequences targeting WordPress theme endpoints
• Monitor web server access logs for suspicious patterns including path traversal attempts and requests for sensitive system files
• Implement file integrity monitoring on critical WordPress configuration files to detect unauthorized access or modifications
• Deploy runtime application self-protection (RASP) solutions capable of detecting file inclusion attacks at the application layer

Monitoring Recommendations

• Enable verbose logging for WordPress and review logs regularly for anomalous file access patterns
• Set up alerts for HTTP requests containing known LFI payloads such as ../, ..%2f, %2e%2e/, or PHP wrapper protocols
• Monitor for unusual PHP process behavior including attempts to read files outside the WordPress installation directory
• Implement network-level monitoring to detect data exfiltration following potential LFI exploitation

How to Mitigate CVE-2026-22428

Immediate Actions Required

• Identify all WordPress installations using the Tooth Fairy theme version 1.16 or earlier
• Disable or remove the vulnerable Tooth Fairy theme until a patched version is available
• Implement Web Application Firewall rules to block LFI attack patterns targeting the theme
• Review server logs for evidence of exploitation attempts and investigate any suspicious activity

Patch Information

Check the Patchstack vulnerability database for updates on available patches from AncoraThemes. WordPress site administrators should update the Tooth Fairy theme to a patched version as soon as one becomes available from the vendor. Until a patch is released, consider switching to an alternative theme or implementing the workarounds described below.

Workarounds

• Replace the Tooth Fairy theme with an alternative WordPress theme that is not affected by this vulnerability
• Implement strict Web Application Firewall rules to filter requests containing path traversal sequences before they reach the application
• Restrict PHP's open_basedir configuration to limit file access to the WordPress installation directory only
• Apply the principle of least privilege to the web server user, limiting its ability to read sensitive system files

# PHP configuration hardening example
# Add to php.ini or .htaccess to restrict file access
php_value open_basedir /var/www/html/wordpress/
php_flag allow_url_include off
php_flag allow_url_fopen off