Vulnerability in WP Fastest Cache – WordPress Cache Plugin — CVE-2026-111464
What to do now
Update WP Fastest Cache – WordPress Cache Plugin to 1.5.4 or later.
Affected versions
- Everything up to and including 1.5.3
Affected: WP Fastest Cache – WordPress Cache Plugin (plugin, wp-fastest-cache)
What the vulnerability is
The WP Fastest Cache plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 1.5.3. The plugin caches the response of Core’s wp-activate.php without honoring its no-store/no-cache headers, the wp-activate-* cookie, or the WP_INSTALLING state, writing the credential-bearing activation response to a publicly accessible cache file. This makes it possible for unauthenticated attackers to retrieve the plaintext username and twelve-character password of the most recently activated Multisite registrant from that cached wp-activate.php response. Exploitation requires a Multisite subdirectory installation with public user and site registration enabled, and the credentials are only exposed after a genuine registrant follows their activation link.