CVE-2026-39549: Aperitif Path Traversal Vulnerability

CVE-2026-39549 Overview

CVE-2026-39549 is an unauthenticated Local File Inclusion (LFI) vulnerability affecting the Aperitif WordPress theme in versions 1.5 and earlier. The flaw maps to CWE-98, improper control of filename for include/require statements in PHP. Remote attackers can manipulate file path parameters to include arbitrary local files from the underlying server. Successful exploitation can disclose sensitive configuration data, source code, or credentials, and in some configurations enable code execution by including attacker-controlled files. The vulnerability was disclosed through Patchstack's WordPress vulnerability database.

Critical Impact
Unauthenticated network attackers can read arbitrary server-side files, including wp-config.php, exposing database credentials and WordPress secret keys.

Affected Products

Aperitif WordPress theme versions <= 1.5
WordPress installations using the vulnerable theme
PHP-based file inclusion code paths within the theme

Discovery Timeline

2026-06-17 - CVE-2026-39549 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2026-39549

Vulnerability Analysis

The Aperitif theme passes user-controlled input into a PHP file inclusion function without sufficient validation. This is the classic pattern described in CWE-98: a PHP Remote File Inclusion via improper neutralization of filename inputs. Because the affected request paths do not require authentication, any remote actor can reach the vulnerable handler.

The Patchstack advisory classifies the issue as Local File Inclusion. An attacker supplies a crafted parameter value that resolves to a server-local path. PHP then includes that file, executing it if it contains PHP or returning its contents in the response.

Root Cause

The root cause is missing allowlist validation and path normalization before the theme passes attacker-controlled input to include, include_once, require, or require_once. Without canonicalization, directory traversal sequences such as ../ can escape the intended template directory and reach files like /etc/passwd or wp-config.php.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker sends an HTTP request to a vulnerable theme endpoint, supplying a path traversal payload in the file or template parameter. The PHP interpreter then loads and processes the referenced file. Refer to the Patchstack WordPress Vulnerability Report for the specific parameter and endpoint details.

No public proof-of-concept exploit code is currently listed in the enriched CVE data, so technical details are described in prose only.

Detection Methods for CVE-2026-39549

Indicators of Compromise

HTTP requests to Aperitif theme paths containing traversal sequences such as ../, ..%2f, or encoded null bytes %00
Web server access logs showing parameter values that reference sensitive files such as wp-config.php, /etc/passwd, or /proc/self/environ
Unexpected PHP include warnings or errors in WordPress debug logs referencing theme files
Outbound web responses returning PHP source or configuration content from theme request handlers

Detection Strategies

Inspect web access logs for query parameters containing path traversal patterns directed at /wp-content/themes/aperitif/ URLs
Deploy WAF rules that block traversal sequences and absolute paths in theme parameters
Monitor for HTTP 200 responses to theme endpoints whose response bodies contain markers like DB_PASSWORD, AUTH_KEY, or root:x:
Hash and baseline theme files; alert on unexpected access patterns to non-template files from the PHP process

Monitoring Recommendations

Enable verbose WordPress and PHP error logging and forward logs to a central SIEM for correlation
Track requests to the Aperitif theme with high cardinality of unique parameter values, indicating fuzzing
Alert on PHP processes opening files outside the WordPress document root

How to Mitigate CVE-2026-39549

Immediate Actions Required

Identify all WordPress sites using the Aperitif theme and confirm installed version against <= 1.5
Take vulnerable sites offline or place behind a WAF that blocks traversal payloads until a fix is applied
Rotate any secrets stored in wp-config.php, including database credentials and WordPress salts, if exposure is suspected
Review web server logs for prior exploitation attempts and signs of file disclosure

Patch Information

At the time of NVD publication, the enriched CVE data does not list a vendor patch URL beyond the Patchstack advisory. Administrators should consult Patchstack and the theme distribution channel for an updated release beyond version 1.5, and apply it once available.

Workarounds

Deactivate and remove the Aperitif theme until a patched version is released
Deploy WAF or ModSecurity rules that reject requests containing ../, encoded traversal sequences, or absolute filesystem paths in query parameters
Restrict PHP open_basedir to the WordPress installation directory to limit file inclusion scope
Set filesystem permissions so the PHP process cannot read wp-config.php after credentials are loaded, where the hosting stack supports it

bash

# Example php.ini hardening to limit file inclusion scope
open_basedir = "/var/www/html/:/tmp/"
allow_url_include = Off
allow_url_fopen = Off