The Mosaic Generator plugin for WordPress suffers from a stored XSS vulnerability (CWE-80) due to insufficient sanitization and escaping of the ‘c’ parameter in all versions up to 1.0.5. Authenticated attackers with Contributor or higher privileges can inject arbitrary scripts that execute in the context of users viewing the injected pages. This vulnerability can lead to limited confidentiality and integrity impacts but does not affect availability. The CVSS 3.1 vector indicates network attack vector, low attack complexity, requiring privileges, no user interaction, and scope change.

Successful exploitation allows an authenticated user with Contributor-level access or higher to inject malicious scripts that execute in other users' browsers when they view the affected pages. This can lead to limited confidentiality and integrity impacts such as session hijacking or unauthorized actions performed on behalf of users. There is no impact on system availability. No known exploits are reported in the wild.

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 Mosaic Generator plugin if possible. Monitor for updates from the vendor regarding patches or official mitigations.