CVE-2026-109208 in LearnPress Plugin
Summary
by MITRE • 10/17/2026
The LearnPress – WordPress LMS Plugin for Create and Sell Online Courses plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'quantity (REST) / order_comments (checkout)' parameter in all versions up to, and including, 4.4.10 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. With guest checkout enabled the attack is fully unauthenticated; with guest checkout disabled, any Subscriber-level user can exploit both vectors through their own checkout.
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Analysis
by VulDB Data Team • 10/17/2026
The LearnPress plugin, widely utilized for creating and selling online courses on WordPress platforms, contains critical security vulnerabilities in versions up to 4.4.10 that allow for stored cross-site scripting attacks. These flaws stem from insufficient input sanitization and a lack of proper output escaping within the REST API endpoint handling order quantities and the checkout process comments field. The core technical issue lies in the application's failure to validate or encode user-supplied data before storing it in the database, as well as its subsequent failure to escape this data when rendering it back into HTML pages for other users. This architectural oversight creates a persistent vector where malicious scripts can be embedded directly into legitimate content structures, such as order records and checkout comments, which are then served to visitors without modification.
The operational impact of these vulnerabilities is significant because they enable unauthenticated attackers to inject arbitrary web scripts that execute in the context of any user who views the affected pages. When guest checkout is enabled on a WordPress site, an attacker does not need valid credentials or even a registered account to exploit this flaw; they can simply submit malicious payloads through public-facing forms associated with these parameters. Even if guest checkout is disabled, the vulnerability remains exploitable by any subscriber-level user who has access to the checkout process. In such scenarios, attackers can leverage their own accounts to inject scripts that will subsequently execute when administrators or other users view order details and comments, facilitating a broad range of malicious activities including session hijacking, credential theft, defacement, or redirection to phishing sites.
From an industry standards perspective, this vulnerability aligns with CWE-79, which classifies improper neutralization of input during web page generation as the root cause for cross-site scripting flaws. The attack methodology corresponds closely to MITRE ATT&CK technique T1059, specifically sub-techniques involving command and script interpreters or browser-based execution, depending on how the injected payload is structured. Furthermore, because the malicious content persists in the database and affects multiple users over time, it also reflects characteristics of CWE-83, which covers stored cross-site scripting where data is not validated before being added to a web application's storage. The persistence aspect distinguishes this from reflected XSS attacks, making remediation more urgent as each affected page serves as a potential attack vector for every visitor.
Mitigation strategies must prioritize immediate patching of the LearnPress plugin to version 4.4.11 or later, where these sanitization and escaping issues have been addressed by the developers. Until an update is applied, site administrators should consider disabling guest checkout if feasible, although this only mitigates half of the attack surface since subscriber-level users can still exploit the vulnerability. Implementing a Web Application Firewall with rules specifically tuned to detect and block XSS payloads in REST API requests and form submissions can provide temporary protection by filtering malicious inputs before they reach the application logic. Additionally, enforcing strict Content Security Policy headers that restrict script execution sources can help mitigate the impact of any successfully injected scripts by preventing them from executing unless explicitly allowed by policy directives. Regular security audits focusing on input validation and output encoding practices across all custom plugins are essential to prevent similar vulnerabilities in future development cycles.