Yes. Using the default password on your ZTE F6640 is a significant security risk.
Action Item: Even if you don't want to change your Wi-Fi name, at least change the admin panel password.
Finding the right ZTE F6640 password boils down to two questions: Who is your ISP? and Do you still have the physical sticker? zte f6640 password
Remember, these passwords exist to protect your home network. Treat your router like the front door of your digital house—change the locks from the default "builder grade" keys to something unique.
Still locked out? Contact your ISP's technical support. They can send a "re-provisioning signal" that resets the password on their end without you needing physical access to the router. Action Item: Even if you don't want to
Disclaimer: Passwords vary by firmware version and ISP customization. This guide is for informational purposes to help owners access their own legally purchased hardware.
Unlike a generic router you buy at a store, the ZTE F6640 is almost exclusively supplied by ISPs. Therefore, the default credentials vary significantly depending on which company provided the device. Remember, these passwords exist to protect your home network
There is no single "universal" password. Below are the most common default combinations.
Go to: Network -> WLAN -> Security