MapSVG WordPress Plugin Vulnerability Allows Arbitrary File Uploads (CVE-2026-1771)

The MapSVG plugin for WordPress versions up to and including 8.14.0 is susceptible to an arbitrary file upload vulnerability, identified as CVE-2026-1771. This flaw stems from inadequate file type validation within the SVGFile constructor, specifically due to an incorrect conditional check that bypasses necessary validation. This allows authenticated attackers, who possess Administrator-level privileges or higher, to upload arbitrary malicious files to the affected WordPress server. Successful exploitation of this vulnerability could lead to remote code execution, enabling attackers to take full control of the compromised website and potentially the underlying server infrastructure.

Attack Chain

1. An attacker obtains or possesses Administrator-level credentials for a WordPress instance running the vulnerable MapSVG plugin (versions up to and including 8.14.0).
2. The attacker logs into the WordPress administrative interface using the compromised credentials.
3. Leveraging the vulnerable functionality of the MapSVG plugin, the attacker crafts and sends a request to upload a malicious file (e.g., a PHP web shell), exploiting the missing file type validation (CVE-2026-1771).
4. The web server processes the upload, and due to the vulnerability, the malicious file is successfully stored on the server, typically within a publicly accessible directory associated with the MapSVG plugin.
5. The attacker sends a subsequent HTTP GET request to the known or inferred URL of the newly uploaded malicious file (e.g., wp-content/plugins/mapsvg/uploads/shell.php).
6. The web server executes the malicious script, granting the attacker remote code execution capabilities on the underlying system.
7. The attacker uses the web shell to issue arbitrary commands, interact with the server's file system, exfiltrate sensitive data, or establish further persistence on the compromised server.

Impact

Successful exploitation of CVE-2026-1771 can grant attackers remote code execution capabilities on the affected WordPress server. This can lead to full compromise of the website, including data theft, defacement, injection of malware, or the use of the compromised server as a platform for further attacks. The vulnerability impacts any organization using the specified versions of the MapSVG plugin, making their WordPress sites vulnerable to complete takeover by authenticated administrative users.

Recommendation

• Patch the MapSVG WordPress plugin to a version greater than 8.14.0 immediately to address CVE-2026-1771.
• Deploy the Sigma rule "Detect Access to Suspicious Files in MapSVG Plugin Directory (CVE-2026-1771)" to your SIEM to identify attempts to execute uploaded web shells.
• Monitor webserver logs for HTTP GET requests to unusual file extensions (e.g., .php, .jsp, .asp) within the /wp-content/plugins/mapsvg/ directory.
• Review web server access logs for any POST requests that result in executable files being placed in unexpected locations within WordPress directories.