CVE-2026-56066 Overview
CVE-2026-56066 is an unauthenticated arbitrary file deletion vulnerability affecting the ShortPixel Adaptive Images plugin for WordPress in versions up to and including 3.11.4. The flaw is categorized under [CWE-22] (Improper Limitation of a Pathname to a Restricted Directory), commonly known as Path Traversal. An unauthenticated remote attacker can send crafted requests to delete files accessible to the web server process. Successful exploitation may remove non-critical files, impacting site availability without requiring credentials or user interaction.
Critical Impact
Remote unauthenticated attackers can delete files on affected WordPress installations, degrading availability across sites running vulnerable versions of the plugin.
Affected Products
- ShortPixel Adaptive Images WordPress plugin versions <= 3.11.4
- WordPress sites with the plugin installed and network-reachable
- Fixed in ShortPixel Adaptive Images version 3.11.5
Discovery Timeline
- 2026-06-26 - CVE-2026-56066 published to NVD
- 2026-06-26 - Last updated in NVD database
Technical Details for CVE-2026-56066
Vulnerability Analysis
The vulnerability resides in file handling logic exposed by the ShortPixel Adaptive Images plugin. The plugin fails to validate or restrict pathnames supplied through requests, allowing traversal outside the intended directory. Because the affected endpoint does not require authentication, any remote actor can reach the vulnerable functionality. The [CWE-22] classification confirms the plugin does not properly canonicalize or constrain input paths before performing file deletion.
The impact is limited to availability. Confidentiality and integrity are not directly affected according to the assessment, but deleting configuration or cache files can trigger broader site errors. The scope is marked as changed, indicating the vulnerable component can affect resources beyond its own security context. See the Patchstack Vulnerability Report for reference.
Root Cause
The root cause is missing input validation on a file path parameter processed by the plugin. The code accepts user-controlled path components and passes them to a filesystem deletion routine without enforcing an allowlist or resolving paths against a permitted base directory. Traversal sequences such as ../ reach files outside the intended scope.
Attack Vector
An attacker sends an HTTP request to the vulnerable plugin endpoint over the network. No authentication or user interaction is required. The attacker supplies a manipulated path parameter referencing a target file. The plugin resolves and deletes the file, resulting in availability loss. No verified public exploit is currently associated with this CVE, and its EPSS probability sits in the lower range.
No verified public proof-of-concept is available. Refer to the Patchstack advisory for technical details on the vulnerable parameter and fixed code path.
Detection Methods for CVE-2026-56066
Indicators of Compromise
- HTTP requests to ShortPixel Adaptive Images plugin endpoints containing path traversal sequences such as ../ or URL-encoded equivalents (%2e%2e%2f).
- Unexpected deletion of files under wp-content/, plugin directories, or WordPress core paths.
- Web server access logs showing unauthenticated POST or GET requests to plugin PHP handlers followed by missing files.
Detection Strategies
- Inspect WordPress and web server logs for requests targeting ShortPixel Adaptive Images plugin scripts with suspicious path parameters.
- Deploy web application firewall (WAF) rules that block traversal patterns directed at the plugin's endpoints.
- Correlate filesystem change events with inbound HTTP requests to identify deletion activity tied to plugin URIs.
Monitoring Recommendations
- Monitor file integrity across wp-content/plugins/shortpixel-adaptive-images/ and adjacent directories.
- Alert on 200-response requests to plugin endpoints originating from unauthenticated sessions with encoded path characters.
- Track plugin version inventory across managed WordPress fleets to identify hosts still running <= 3.11.4.
How to Mitigate CVE-2026-56066
Immediate Actions Required
- Update the ShortPixel Adaptive Images plugin to version 3.11.5 or later on all WordPress installations.
- If patching is delayed, deactivate and remove the plugin until the update can be applied.
- Review recent web server and WordPress logs for exploitation attempts targeting the plugin.
Patch Information
The vendor addressed the issue in ShortPixel Adaptive Images version 3.11.5. Details are published in the Patchstack Vulnerability Report. Apply the update through the WordPress plugin manager or via WP-CLI.
Workarounds
- Restrict access to plugin endpoints using WAF or web server rules until the patch is applied.
- Enforce least-privilege filesystem permissions on the WordPress web user to limit files eligible for deletion.
- Maintain current, tested backups of WordPress files and databases to enable rapid recovery.
# Update the plugin via WP-CLI
wp plugin update shortpixel-adaptive-images --version=3.11.5
# Verify installed version
wp plugin get shortpixel-adaptive-images --field=version
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
