The UltraEmbed – Advanced Iframe Plugin for WordPress with Gutenberg Block Included suffers from a stored cross-site scripting vulnerability (CWE-79) in its 'iframe' shortcode implementation. This vulnerability arises from improper neutralization of input during web page generation, specifically due to insufficient input sanitization and output escaping of user-supplied attributes. Authenticated attackers with contributor or higher privileges can inject arbitrary JavaScript code that executes in the context of users visiting the compromised pages. This can lead to information disclosure or session hijacking. The vulnerability affects all versions up to 1.0.3. The CVSS 3.1 base score is 6.4 (medium severity), reflecting network attack vector, low attack complexity, privileges required, no user interaction, and partial confidentiality and integrity impact. No patch or official fix has been documented in the provided data.

Successful exploitation allows authenticated users with contributor-level or higher privileges to inject and store malicious scripts within pages using the vulnerable shortcode. These scripts execute in the browsers of users who view the affected pages, potentially leading to information disclosure or unauthorized actions performed in the context of the victim's session. The vulnerability does not impact availability. There are no known exploits in the wild as of the provided information.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict contributor-level access to trusted users only and consider disabling or removing the UltraEmbed plugin if feasible. Monitor vendor channels for updates and apply patches promptly once released.