CVE-2026-83562 in WCFM Marketplace Plugin
Summary
by MITRE • 09/02/2026
Contributor Cross Site Scripting (XSS) in WCFM Marketplace <= 3.8.2 versions.
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Analysis
by VulDB Data Team • 09/02/2026
The vulnerability identified as Contributor Cross-Site Scripting within the WFCM Marketplace plugin for WordPress, affecting versions up to and including 3.8.2, represents a significant security risk associated with insufficient input validation and output encoding in user-facing administrative interfaces. This flaw specifically targets roles designated as contributors or lower-level users who possess limited capabilities but are granted access to specific frontend forms that interact directly with the plugin's backend logic without adequate sanitization of submitted data. The core technical deficiency lies in the application's failure to properly escape special characters within HTML contexts when rendering user-provided content, allowing an attacker to inject malicious JavaScript payloads into pages viewed by other users or administrators who have higher privilege levels.
From a technical perspective, this vulnerability is classified under CWE-79, which denotes Improper Neutralization of Input During Web Page Generation commonly known as Cross-Site Scripting. The attack vector typically involves the submission of crafted input through forms such as product descriptions, store information fields, or other editable content areas accessible to contributors. When this malicious data is stored in the database and subsequently retrieved for display on a webpage without proper encoding, it executes within the context of the victim's browser session. This execution environment grants the injected script access to sensitive cookies, local storage tokens, and potentially administrative functions if viewed by an admin user, thereby facilitating account takeover or further exploitation of the WordPress installation.
The operational impact of this vulnerability extends beyond simple defacement or minor data theft. Because WCFM Marketplace is a complex e-commerce solution that handles financial transactions and customer data, successful exploitation can lead to severe business disruption. An attacker could perform session hijacking by stealing administrator cookies, leading to complete control over the marketplace backend. This includes the ability to modify product listings, alter pricing structures, access sensitive order information, or install additional malicious plugins. Furthermore, in multi-vendor environments where multiple store owners interact with a central dashboard, an XSS payload injected by one contributor could target other vendors or site administrators, creating a chain reaction of compromise across different user accounts within the same ecosystem.
This vulnerability aligns closely with MITRE ATT&CK technique T1059, specifically sub-technique 007 which covers JavaScript execution in web browsers. The exploitation strategy relies on social engineering or direct access to contributor-level interfaces to deliver the payload, followed by waiting for a privileged user to view the compromised content. This passive delivery mechanism makes it particularly dangerous as it does not require active interaction beyond viewing the affected page, increasing the likelihood of successful compromise against unsuspecting administrators who regularly monitor marketplace activities and vendor submissions.
Mitigation strategies must prioritize immediate patching to version 3.8.3 or later where this issue has been addressed through improved input sanitization and output encoding practices. For organizations unable to update immediately due to compatibility constraints, implementing a Web Application Firewall with rules specifically tuned to detect and block XSS payloads in form submissions can provide an additional layer of defense. Additionally, enforcing strict Content Security Policy headers that restrict the execution of inline scripts can significantly reduce the impact of any successfully injected code. Regular security audits focusing on role-based access control and input validation across all user-facing forms are essential to prevent similar vulnerabilities from being introduced during future development cycles or through third-party integrations within the WCFM ecosystem.