CVE-2025-0863 identifies a stored cross-site scripting vulnerability in the Flexmls® IDX Plugin for WordPress, specifically within the 'idx_frame' shortcode functionality. The vulnerability stems from improper neutralization of input during web page generation (CWE-79), where user-supplied attributes are neither adequately sanitized nor escaped before rendering. This flaw enables authenticated attackers with contributor-level permissions or higher to inject arbitrary JavaScript code into pages generated by the plugin. Because the malicious script is stored persistently, it executes in the context of any user who accesses the affected page, potentially compromising session tokens, redirecting users, or performing unauthorized actions on behalf of victims. The vulnerability affects all plugin versions up to and including 3.14.27. Exploitation requires authentication but no user interaction, and the attack vector is network-based. The CVSS v3.1 base score is 6.4, reflecting low attack complexity and privileges required, with a scope change due to impact on other components. No patches or official fixes are currently linked, and no known exploits have been reported in the wild. The vulnerability highlights the risks of insufficient input validation in WordPress plugins, especially those handling dynamic content and user inputs.

The impact of CVE-2025-0863 is significant for organizations using the Flexmls® IDX Plugin on WordPress sites, particularly real estate businesses relying on IDX integration for property listings. Successful exploitation can lead to session hijacking, unauthorized actions performed in the context of legitimate users, theft of sensitive information, and potential defacement or redirection of website visitors. Since the injected scripts execute in the browsers of all users accessing the compromised pages, the attack surface includes site administrators, editors, and end-users, potentially leading to widespread compromise. The vulnerability could also facilitate further attacks such as phishing, malware distribution, or lateral movement within the organization’s network. Although exploitation requires contributor-level access, this is a relatively low privilege level, increasing the risk if user accounts are compromised or improperly assigned. The lack of user interaction needed for exploitation further elevates the threat. Overall, this vulnerability can damage organizational reputation, lead to data breaches, and disrupt business operations.

To mitigate CVE-2025-0863, organizations should immediately restrict contributor-level access to trusted users only, minimizing the risk of malicious script injection. Administrators should audit existing content for suspicious shortcode usage and remove or sanitize any potentially injected scripts. Applying strict Content Security Policy (CSP) headers can help limit the impact of injected scripts by restricting script sources and execution contexts. Until an official patch is released, consider disabling or removing the Flexmls® IDX Plugin if feasible, or replacing it with alternative IDX solutions that follow secure coding practices. Developers and site administrators should implement rigorous input validation and output escaping for all user-supplied data, especially in shortcode attributes. Monitoring logs for unusual activity and scanning for XSS payloads can help detect exploitation attempts early. Finally, maintain regular backups and have an incident response plan ready to address potential compromises stemming from this vulnerability.