CVE-2026-15786: WP Encryption Path Traversal Vulnerability

CVE-2026-15786 Overview

CVE-2026-15786 is a directory traversal vulnerability in the WP Encryption WordPress plugin, which provides one-click free SSL certificate installation, HTTPS redirection, and SSL scanning capabilities. The flaw exists in all versions up to and including 7.8.6.6 through improper handling of the imploded parameter. Authenticated attackers with administrator-level access can read arbitrary files on the server, exposing sensitive configuration data. The vulnerability also allows writes to plaintext configuration files such as .htaccess, enabling denial-of-service or redirect attacks. Although output is passed through esc_html() to encode angle brackets and prevent direct PHP execution, the write primitive remains exploitable against non-PHP configuration files. The vulnerability is classified under [CWE-22] (Path Traversal).

Critical Impact
Authenticated administrators can read arbitrary server files and write to plaintext configuration files including .htaccess, enabling information disclosure, denial-of-service, and malicious redirects.

Affected Products

WP Encryption – One Click Free SSL Certificate plugin for WordPress
All versions up to and including 7.8.6.6
Plugin slug: wp-letsencrypt-ssl

Discovery Timeline

2026-07-23 - CVE-2026-15786 published to NVD
2026-07-23 - Last updated in NVD database

Technical Details for CVE-2026-15786

Vulnerability Analysis

The vulnerability exists in the WP Encryption plugin's le_admin.php file, where the imploded parameter is used to construct file paths without adequate sanitization. Attackers who possess administrator-level WordPress credentials can supply traversal sequences such as ../ to escape the intended directory. This grants read access to arbitrary files on the underlying filesystem, including wp-config.php, private keys, and system files readable by the web server user.

The plugin also uses the tainted path in write operations. While content undergoes esc_html() processing, which converts characters like < and > into HTML entities, this only defeats direct PHP code injection. Plaintext configuration files that do not rely on angle-bracket syntax remain fully controllable by an attacker.

Root Cause

The root cause is missing path canonicalization and validation on the imploded parameter within the plugin's administrative handlers at lines 150, 2120, and 2138 of le_admin.php. User-supplied input is concatenated into filesystem paths without normalizing traversal sequences or restricting operations to an allowlisted directory.

Attack Vector

Exploitation requires authenticated access at the administrator role or higher. An attacker submits a crafted request to the vulnerable plugin endpoint with the imploded parameter containing directory traversal payloads. The plugin then reads or writes the targeted file. For write-based attacks, attackers commonly target .htaccess to inject rewrite rules that redirect visitors to attacker-controlled infrastructure or to break site availability.

The vulnerability mechanism is described in the Wordfence Vulnerability Analysis and the WordPress Plugin Change Set that resolves it.

Detection Methods for CVE-2026-15786

Indicators of Compromise

HTTP requests to WP Encryption plugin admin endpoints containing imploded parameter values with ../ or URL-encoded %2e%2e%2f sequences.
Unexpected modifications to .htaccess files containing new RewriteRule or Redirect directives pointing to external domains.
Access log entries showing administrator-authenticated POST requests reading files outside the plugin's directory tree.
Unusual outbound traffic from site visitors indicating redirect chains originating from the compromised WordPress site.

Detection Strategies

Monitor WordPress access logs for requests to le_admin.php handlers containing traversal patterns in query strings or POST bodies.
Implement file integrity monitoring on .htaccess, wp-config.php, and other WordPress core configuration files.
Alert on administrator account activity that reads server files outside the standard WordPress directory structure.
Correlate admin authentication events with subsequent filesystem access anomalies.

Monitoring Recommendations

Enable verbose logging on the WordPress site and forward events to a centralized SIEM for correlation.
Track plugin version inventory across managed WordPress sites to identify hosts running versions at or below 7.8.6.6.
Baseline normal administrator behavior and alert on deviations involving plugin-driven file operations.

How to Mitigate CVE-2026-15786

Immediate Actions Required

Update the WP Encryption plugin to a version later than 7.8.6.6 as soon as the vendor releases a patched build.
Audit .htaccess files and other plaintext configuration files for unauthorized modifications and restore known-good copies where needed.
Rotate credentials, API keys, and secrets stored in wp-config.php if administrator accounts may have been compromised.
Review WordPress administrator accounts and remove or reduce privileges for any account that does not require the role.

Patch Information

The fix is tracked in the WordPress Plugin Change Set 3617401. Administrators should verify the installed plugin version through the WordPress admin dashboard and upgrade using the plugin manager or WP-CLI. Refer to the Wordfence Vulnerability Analysis for detailed remediation guidance.

Workarounds

Temporarily deactivate the WP Encryption plugin until the patched version is installed.
Restrict WordPress administrator access to trusted IP addresses using web server or WAF rules.
Deploy a Web Application Firewall rule that blocks requests containing directory traversal sequences in the imploded parameter.
Enforce multi-factor authentication for all WordPress administrator accounts to reduce the risk of credential compromise required for exploitation.

bash

# Configuration example: WP-CLI check and update
wp plugin get wp-letsencrypt-ssl --field=version
wp plugin update wp-letsencrypt-ssl