CVE-2026-6147 in LightSync Pro Plugin
Summary
by MITRE • 08/05/2026
The LightSync Pro plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the rest_replace_media() function in all versions up to, and including, 2.1.6. This makes it possible for authenticated attackers, with Author-level access and above, to upload arbitrary files on the affected site's server which may make remote code execution possible.
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Analysis
by VulDB Data Team • 08/05/2026
The LightSync Pro plugin for WordPress presents a critical security vulnerability through its inadequate file type validation mechanisms within the rest_replace_media() function, affecting all versions up to and including 2.1.6. This flaw represents a significant weakness in the plugin's security architecture that directly enables unauthorized file operations on vulnerable WordPress installations. The vulnerability stems from insufficient input sanitization and validation processes that fail to properly examine uploaded file characteristics before storage on the server filesystem.
The technical implementation of this vulnerability allows authenticated users with Author-level privileges or higher to bypass normal file upload restrictions through the REST API endpoint exposed by the plugin. When attackers exploit this flaw, they can submit malicious files through the rest_replace_media() function without proper validation of file extensions, MIME types, or content signatures. This missing validation creates an attack surface where arbitrary file uploads become possible, fundamentally undermining the security boundaries typically established by WordPress user role permissions and file upload restrictions.
The operational impact of this vulnerability extends beyond simple unauthorized file uploads to potentially enable full remote code execution capabilities on affected servers. Attackers can leverage this privilege escalation vector to upload web shells, malicious scripts, or other payload files that can be executed within the context of the web server process. This represents a severe compromise of system integrity and confidentiality, as the vulnerability allows attackers to establish persistent access points and potentially escalate privileges further within the compromised environment.
Security professionals should recognize this vulnerability as falling under CWE-434 Unrestricted Upload of File with Dangerous Type, which specifically addresses the risks associated with accepting files without proper validation of their type and content. The attack pattern aligns with ATT&CK technique T1505.003 Server-Side Request Forgery where adversaries can manipulate server-side processes to accept malicious payloads through legitimate API endpoints. Organizations should implement immediate mitigations including plugin version updates, REST API endpoint restrictions, and enhanced file validation mechanisms that enforce strict content type checking.
The remediation strategy must prioritize the immediate upgrade of LightSync Pro to versions that address this validation flaw while implementing additional defensive measures such as restricting file upload capabilities for lower-privilege users and monitoring REST API traffic for suspicious file upload activities. Network-level protections should include web application firewalls that can detect and block malicious file upload attempts, while server-side controls should enforce strict file type validation using multiple verification methods including content inspection, extension filtering, and MIME type verification to prevent exploitation of similar vulnerabilities in other components.