CVE-2025-12652 is a stored Cross-Site Scripting (XSS) vulnerability identified in the Ungapped Widgets plugin for WordPress, maintained by oscaruribe. The vulnerability arises from improper neutralization of user-supplied input in the 'prefillvalues' parameter within the ungapped-form shortcode. Specifically, the plugin fails to adequately sanitize and escape this parameter, allowing authenticated users with contributor-level or higher privileges to inject arbitrary JavaScript code into pages. When other users visit these pages, the injected scripts execute in their browsers, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim. The vulnerability affects all versions up to and including version 1 of the plugin. The CVSS v3.1 base score is 6.4, reflecting a medium severity with network attack vector, low attack complexity, and requiring privileges but no user interaction. The scope is changed, indicating that the vulnerability can impact resources beyond the vulnerable component. No public exploits have been reported yet, but the vulnerability poses a significant risk in environments where contributor-level users are present. The root cause is insufficient input validation and output encoding during web page generation, categorized under CWE-79. The vulnerability was published on November 11, 2025, and assigned by Wordfence. No official patches or updates are currently linked, so mitigation relies on restricting user privileges or applying manual sanitization.

This vulnerability can have significant impacts on organizations using the Ungapped Widgets plugin on WordPress sites. An attacker with contributor-level access can inject persistent malicious scripts that execute in the browsers of site visitors or administrators, potentially leading to session hijacking, theft of sensitive information such as cookies or credentials, and unauthorized actions performed with the victim's privileges. This can result in data breaches, defacement, or further compromise of the web application and backend systems. Since WordPress is widely used globally, any organization relying on this plugin is at risk, especially those with multiple contributors or editors. The vulnerability does not directly affect availability but compromises confidentiality and integrity. The medium CVSS score reflects that exploitation requires authenticated access, limiting the attack surface but still posing a serious threat in collaborative environments. Without timely mitigation, attackers could leverage this flaw to escalate privileges or move laterally within the affected environment.

1. Immediately restrict contributor-level and higher user privileges on WordPress sites using the Ungapped Widgets plugin until a patch is available. 2. Implement strict input validation and output encoding for the 'prefillvalues' parameter in the shortcode if custom development is possible. 3. Monitor and audit user-generated content for suspicious scripts or injected code. 4. Employ Web Application Firewalls (WAFs) with rules to detect and block common XSS payloads targeting this parameter. 5. Educate content contributors about the risks of injecting untrusted content and enforce least privilege principles. 6. Regularly update the plugin once the vendor releases a patch addressing this vulnerability. 7. Consider disabling or replacing the plugin if immediate patching is not feasible. 8. Use Content Security Policy (CSP) headers to reduce the impact of potential XSS attacks by restricting script execution sources. 9. Conduct security reviews and penetration testing focused on user input handling in WordPress plugins.