The SMTP for SendGrid – YaySMTP WordPress plugin suffers from a stored cross-site scripting vulnerability (CWE-79) due to improper neutralization of input during web page generation. This allows unauthenticated attackers to inject arbitrary web scripts that execute in the context of users visiting the injected pages. The vulnerability affects versions up to and including 1.4. The CVSS 3.1 base score is 7.2, reflecting network attack vector, low attack complexity, no privileges required, no user interaction, and impacts confidentiality and integrity with scope changed.

Successful exploitation can lead to execution of arbitrary scripts in the context of users visiting the affected pages, potentially resulting in theft of sensitive information, session hijacking, or other malicious actions impacting confidentiality and integrity. There is no impact on availability. No known exploits in the wild have been reported.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, users should consider disabling or removing the affected plugin or restricting access to pages where injection could occur. Monitor vendor channels for updates regarding patches or official mitigations.