CVE-2026-56058 in Quform Plugin
Summary
by MITRE • 06/26/2026
Subscriber Arbitrary File Upload in Quform <= 2.23.0 versions.
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Analysis
by VulDB Data Team • 06/26/2026
The Quform plugin for wordpress represents a critical vulnerability landscape where unauthorized file uploads can occur through the subscriber role, potentially leading to remote code execution and complete system compromise. This vulnerability affects versions up to and including 2.23.0, creating a significant security risk for wordpress installations that utilize this form management solution. The flaw stems from inadequate input validation and access control mechanisms within the plugin's file upload functionality, allowing authenticated users with subscriber privileges to bypass security restrictions and upload malicious files to the server.
The technical implementation of this vulnerability resides in the plugin's handling of user-submitted data through form submissions, where proper sanitization checks fail to validate file types and content appropriately. Attackers exploiting this weakness can upload web shells or other malicious payloads that execute with the privileges of the affected wordpress installation. The vulnerability aligns with CWE-434 which specifically addresses insecure file upload scenarios where applications accept untrusted data without proper validation, and it maps to ATT&CK technique T1505.003 for server-side include attacks through file uploads. This particular flaw demonstrates a classic privilege escalation path where low-privileged users can leverage the upload functionality to gain higher system access.
The operational impact of this vulnerability extends beyond simple data compromise, as successful exploitation enables attackers to establish persistent backdoors within wordpress environments. Once uploaded files are executed, threat actors can manipulate database contents, steal sensitive information including user credentials and personal data, modify website content, or use the compromised system as a launchpad for further attacks against internal networks. The vulnerability particularly affects organizations relying on wordpress for their web presence since subscriber accounts often represent legitimate users such as customers or members who may not be expected to have elevated privileges.
Mitigation strategies should focus on immediate plugin updates to versions that address this vulnerability, implementing robust file type restrictions and content validation mechanisms, and applying network-level controls to monitor and block suspicious upload patterns. Organizations must also conduct comprehensive security assessments of their wordpress installations, review user privilege assignments, and establish monitoring procedures for unusual file upload activities. The recommended approach includes deploying web application firewalls with specific rules targeting known malicious file patterns, implementing strict file extension validation, and ensuring that all wordpress plugins are regularly updated from trusted sources to prevent similar vulnerabilities from being exploited in the future.