CVE-2026-39590: Atomlab Path Traversal Vulnerability

CVE-2026-39590 Overview

CVE-2026-39590 is an unauthenticated Local File Inclusion (LFI) vulnerability affecting the Atomlab WordPress theme in versions up to and including 2.4.5. The flaw is categorized under [CWE-98] (Improper Control of Filename for Include/Require Statement in PHP Program). Attackers can exploit the issue over the network without authentication or user interaction. Successful exploitation can disclose sensitive server-side files, expose configuration secrets, and, depending on server configuration, lead to remote code execution.

Critical Impact
An unauthenticated remote attacker can include arbitrary local files through the vulnerable Atomlab theme, leading to information disclosure and potential code execution on the underlying WordPress host.

Affected Products

Atomlab WordPress theme versions <= 2.4.5
WordPress sites bundling the Atomlab theme
Hosting environments running Atomlab with PHP include/require directives enabled

Discovery Timeline

2026-06-17 - CVE-2026-39590 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in the NVD database

Technical Details for CVE-2026-39590

Vulnerability Analysis

The vulnerability stems from improper handling of a filename parameter passed to a PHP include or require statement within the Atomlab theme. Because the affected code path does not require authentication, any unauthenticated attacker can reach it directly over HTTP. The theme accepts attacker-controlled input and uses it to construct a file path that is then loaded by the PHP interpreter. This pattern aligns with [CWE-98], a long-standing class of PHP file inclusion flaws documented by the Patchstack Vulnerability Report. Because PHP evaluates included files as code, the impact extends beyond file disclosure to potential arbitrary code execution when an attacker can stage controllable content on disk.

Root Cause

The root cause is missing or insufficient validation and sanitization of a user-supplied parameter that influences a PHP file inclusion function. The Atomlab theme does not constrain the input to an allow-list of safe template names, nor does it normalize and validate the path before passing it to include/require. As a result, traversal sequences and absolute paths can redirect the inclusion to arbitrary files on the host.

Attack Vector

Exploitation occurs through a crafted HTTP request to a WordPress endpoint exposed by the Atomlab theme. The attacker supplies a path value that points to a sensitive local file such as wp-config.php, /etc/passwd, or log files. If the PHP runtime can read the target file, its contents are returned in the response or executed in the context of the web server user. The high attack complexity reflects the need to identify a usable parameter and a readable target path, but no credentials or user interaction are required.

No verified public proof-of-concept code is available at the time of writing. Refer to the Patchstack Vulnerability Report for additional technical context.

Detection Methods for CVE-2026-39590

Indicators of Compromise

HTTP requests to Atomlab theme paths containing traversal sequences such as ../, ..%2f, or absolute paths like /etc/passwd and wp-config.php.
Web server access logs showing unauthenticated requests with file path parameters returning unusually large or non-HTML responses.
Unexpected PHP errors referencing include(), require(), or failed to open stream in PHP error logs.
Outbound requests or new files appearing in WordPress uploads directories shortly after suspicious LFI request patterns.

Detection Strategies

Inspect WordPress access logs for query parameters that resolve to filesystem paths, especially those targeting wp-config.php, session files, or /proc/self/environ.
Deploy Web Application Firewall (WAF) rules that flag path traversal patterns and PHP wrapper schemes such as php://filter and data://.
Correlate web request anomalies with subsequent PHP process activity, file writes in writable theme directories, or web shell creation.

Monitoring Recommendations

Continuously monitor WordPress installations for theme version <= 2.4.5 of Atomlab using software inventory tooling.
Alert on read access to sensitive files such as wp-config.php by the web server user outside of normal application startup.
Track new or modified PHP files in theme, plugin, and upload directories as a high-fidelity post-exploitation signal.

How to Mitigate CVE-2026-39590

Immediate Actions Required

Identify all WordPress sites running the Atomlab theme at version <= 2.4.5 and update to a fixed release once available from the vendor.
If a patched version is not yet published, disable or remove the Atomlab theme and switch to a maintained alternative.
Rotate any credentials, API keys, and database secrets stored in wp-config.php, as these may have been disclosed.
Review web server and PHP logs for prior exploitation attempts dating back to before the publication date.

Patch Information

No fixed version is referenced in the NVD record at this time. Administrators should consult the Patchstack Vulnerability Report for the latest remediation guidance from the vendor and Patchstack.

Workarounds

Place virtual patching rules at the WAF or reverse proxy to block requests containing path traversal sequences and PHP stream wrappers targeting Atomlab theme endpoints.
Harden PHP by setting open_basedir to restrict file access to the WordPress installation directory and disabling allow_url_include.
Apply least-privilege filesystem permissions so the web server user cannot read sensitive system files outside of the WordPress webroot.

bash

# Example php.ini hardening to limit LFI impact
open_basedir = "/var/www/html:/tmp"
allow_url_include = Off
allow_url_fopen = Off
disable_functions = "system,exec,shell_exec,passthru,popen,proc_open"