Executive brief
The Disable Login Page module for Drupal is designed to block anonymous users from accessing the login form unless they provide a secret key. However, a cache invalidation flaw allows previously cached login pages to remain accessible even after login restrictions are enabled. An attacker can continue accessing the login page despite the protection being in place, potentially leading to unauthorized access attempts.
Technical details
This is an authentication bypass vulnerability in the Disable Login Page Drupal module caused by improper cache handling. The module restricts access to /user/login by requiring a secret key parameter, but does not invalidate relevant caches when the restriction is enabled. As a result, previously cached responses containing the login page remain accessible to unauthenticated users indefinitely until caches are manually cleared. The vulnerability affects versions before 1.1.4 and is exploitable remotely without authentication. The fix requires upgrading to version 1.1.4 or later, which properly invalidates caches when login restrictions are activated.
Affected products
- Drupal Disable Login Page 0.0.0 to 1.1.3
Timeline
- 2026-08-26: disclosed: Security advisory SA-CONTRIB-2026-111 published
- 2026-08-26: patched: Version 1.1.4 released with fix
- 2026-09-02: other: CVE-2026-16647 published on NVD