The WPLG Default Mail From plugin for WordPress suffers from a reflected XSS vulnerability due to insufficient input sanitization and output escaping of the $_SERVER['PHP_SELF'] variable. This flaw exists in all versions up to 1.0.0, enabling unauthenticated attackers to inject malicious scripts that execute in the context of a victim's browser when they interact with a crafted URL. The vulnerability has a CVSS 3.1 score of 6.1, reflecting a network attack vector, low attack complexity, no privileges required, but requiring user interaction, and impacts confidentiality and integrity with no impact on availability.

Successful exploitation can lead to the execution of arbitrary scripts in the context of the victim's browser, potentially allowing theft of sensitive information or session hijacking. The vulnerability affects confidentiality and integrity but does not impact availability. There are no known exploits in the wild at this time.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should consider disabling the plugin or applying manual input sanitization and output escaping if feasible. Avoid clicking on suspicious links that may exploit this vulnerability.