The Simple Membership plugin for WordPress allows an optional auto‑login‑after‑registration feature that, in versions prior to 4.8.3, inadvertently sends a new member's plaintext password in the URL query string. This places the password in the browser history and within any web server, proxy, or CDN access logs that capture the full request, exposing the credential to anyone who can read those artifacts.

Vulnerability affects the Simple Membership WordPress plugin when the version is older than 4.8.3. The plugin is distributed to sites running WordPress; any installation that has not upgraded to 4.8.3 or higher is potentially exposed.

Based on the description, the exploitation requires that an attacker be able to read browser history or logs that contain the URL; it is inferred that the attack vector is local access to logs or browser history, and no remote network exploitation is possible. No network‑based attack vector is required. The CVSS score of 4.7 indicates a medium severity, and the EPSS score of <1% suggests a low chance of exploitation. The vulnerability is not listed in CISA’s KEV catalog, indicating no known widespread exploitation yet. Because plaintext credentials can be retrieved from logs, the impact is compromise of user accounts and potential lateral movement if the same credentials are reused. The lack of a public exploit, coupled with the absence from KEV, suggests the risk is moderate, largely dependent on the exposure of logging infrastructure.