CVE-2026-39553: WaveRide Path Traversal Vulnerability

CVE-2026-39553 Overview

CVE-2026-39553 is a PHP Local File Inclusion (LFI) vulnerability in the Select-Themes WaveRide WordPress theme. The flaw stems from improper control of filename parameters used in PHP include or require statements [CWE-98]. Attackers can manipulate file path inputs to load arbitrary local files through the PHP interpreter. The vulnerability affects all WaveRide theme versions from initial release through version 1.4. Successful exploitation can expose sensitive server-side files and, depending on the server configuration, lead to PHP code execution.

Critical Impact
Network-accessible Local File Inclusion in the WaveRide WordPress theme can disclose sensitive files and enable code execution paths through PHP include/require misuse.

Affected Products

Select-Themes WaveRide WordPress theme versions up to and including 1.4
WordPress installations running the WaveRide theme
Any site exposing the vulnerable theme's PHP endpoints to network requests

Discovery Timeline

2026-06-02 - CVE-2026-39553 published to NVD
2026-06-02 - Last updated in NVD database

Technical Details for CVE-2026-39553

Vulnerability Analysis

The WaveRide theme accepts a user-controlled value that is passed into a PHP file inclusion statement without sufficient validation or allow-listing. When PHP processes include, require, include_once, or require_once with attacker-influenced input, the interpreter loads and executes the referenced file. In WaveRide versions through 1.4, this pattern enables Local File Inclusion via a network-reachable request. An unauthenticated attacker can target the vulnerable endpoint without user interaction, although the attack complexity is elevated and may require specific preconditions to succeed. The impact spans confidentiality, integrity, and availability because included PHP files execute in the context of the web server process.

Root Cause

The root cause is improper control of a filename used in a PHP include/require statement, classified under [CWE-98]. The theme does not constrain the inclusion target to a fixed directory, does not normalize traversal sequences, and does not enforce an allow-list of permitted file identifiers. As a result, attacker-supplied values reach the PHP file resolution layer directly.

Attack Vector

The attack vector is network-based. An attacker issues an HTTP request to a WaveRide theme endpoint and supplies a crafted parameter that reaches the vulnerable inclusion call. The injected value can reference local files such as PHP configuration files, log files, or session data. If the attacker can stage PHP content in a writable local path (for example, via uploaded files or poisoned logs), the inclusion call can execute that content. No verified public proof-of-concept is currently published. See the Patchstack Vulnerability Report for advisory details.

Detection Methods for CVE-2026-39553

Indicators of Compromise

HTTP requests to WaveRide theme PHP files containing path traversal sequences such as ../, ..%2f, or URL-encoded null bytes
Web server access logs showing parameter values referencing system paths like /etc/passwd, wp-config.php, or php://filter
Unexpected PHP errors referencing include() or require() failures with attacker-controlled paths
Outbound requests from the web server to attacker-controlled hosts following anomalous theme requests

Detection Strategies

Inspect WordPress access logs for requests targeting WaveRide theme files with file-path parameters
Deploy web application firewall (WAF) rules that flag LFI patterns in query strings and POST bodies
Monitor PHP error logs for failed to open stream or Failed opening required entries tied to theme requests
Correlate theme requests with subsequent file reads of sensitive paths on the host

Monitoring Recommendations

Track WordPress theme inventory and version data across managed sites to identify WaveRide installations at version 1.4 or earlier
Enable file integrity monitoring on wp-config.php, PHP session directories, and web-writable upload paths
Alert on process lineage where the PHP-FPM or web server process spawns shells or network utilities

How to Mitigate CVE-2026-39553

Immediate Actions Required

Identify all WordPress sites running the Select-Themes WaveRide theme and determine the installed version
Disable or replace the WaveRide theme on any site running version 1.4 or earlier until a fixed release is confirmed
Restrict access to vulnerable theme endpoints at the WAF or reverse proxy layer
Review web server and PHP logs for prior exploitation attempts referencing local file paths

Patch Information

No fixed version is referenced in the published advisory at the time of disclosure. Administrators should consult the Patchstack Vulnerability Report and the Select-Themes vendor channel for an updated WaveRide release that addresses CVE-2026-39553.

Workarounds

Block requests containing LFI signatures such as ../, php://, file://, and encoded traversal sequences at the WAF
Set the PHP open_basedir directive to restrict file access to the WordPress document root
Disable PHP wrappers by configuring allow_url_include=Off and allow_url_fopen=Off in php.ini
Apply least-privilege file permissions so the PHP runtime cannot read sensitive system files

bash

# Configuration example: harden php.ini against file inclusion abuse
allow_url_include = Off
allow_url_fopen = Off
open_basedir = "/var/www/html:/tmp"
disable_functions = "exec,passthru,shell_exec,system,proc_open,popen"