CVE-2026-11405

The web server binary /bin/httpd contains a hidden backdoor authentication mechanism in the login() function at 004c88b8. - The function contains a normal authentication path using MD5/hash-based password verification (prod_encode64/PasswordToMd5/check_rand_key). - After normal authentication fails, it calls GetValue("sys.rzadmin.password") to read a backdoor password from the device configuration. - It performs a direct strcmp() comparison (plaintext, not hashed) between the config value and the user-supplied password. A successful match grants role=2 (admin-level access) and creates a valid session. The rzadmin username is never checked — any username works with the backdoor

Affected products

Ac10, Ac5, Ac6, Fh1201, W15E

CVSS 3.1

9.8 CRITICAL

EPSS

0.8% (53th percentile)

NVD status

Deferred

Published

2026-07-06