CVE-2026-53953: GetSimple CMS: Predictable Password Reset Password Allows Administrator Account Takeover
GetSimple CMS is a content management system (CMS), and GetSimple CMS CE is the community edition of that CMS. In version 3.3.22, the password reset endpoint can be accessed without authentication. When a reset request is submitted for an existing user, the application generates a new temporary password and immediately stores its hash as the user's new password. The temporary password is generated using PHP rand() seeded with microtime(). Because this seed is time-based and has a limited effective search space, an attacker can generate possible reset password candidates. Since the admin login endpoint does not enforce rate limiting or account lockout, these candidates can be tested online until the correct password is found. Successful exploitation may lead to administrator account takeover. At time of publication, there are no publicly available patches.
Affected Software
Event History
Frequently Asked Questions
What must an attacker be able to do to take over an administrator account?
An attacker needs network access to the unauthenticated password reset endpoint and must submit a reset request for an existing user. They can then generate candidate temporary passwords from the time-based PHP rand() seed and test them against the login endpoint.
Why is online password guessing practical in this case?
The temporary password is generated using PHP rand() seeded with microtime(), which has a limited effective search space. The login endpoint does not enforce rate limiting or account lockout, allowing candidates to be tested online until the correct password is found.
Are deployments affected without an attacker first obtaining credentials?
Yes. The password reset endpoint is accessible without authentication, and the issue can affect an existing administrator account through the reset flow. No prior credentials are required.
What can be done if a patch is not available?
No publicly available patches were available at publication. Restrict network access to the password reset and administrator login endpoints where possible, and add rate limiting or account lockout controls in front of the login endpoint.