How can I change the master password of pgAdmin 4 without resetting it?

pgAdmin 4 has a master password which

is required to secure and later unlock the saved server passwords. This is applicable only for desktop mode users.

I know my current master password, however, I want to change it without resetting it, as

Resetting the master password will also remove all saved passwords and close all existing established connections.

Is this possible?

Nope. Not possible. The reason is that the master password is the decryption key for the saved credentials. Changing the password changes the derived decryption key, which makes the existing data unretrievable (without a little effort and a recent backup). This bit from the documentation hints at how the password is used:

The master password is not stored anywhere on the physical storage. It is temporarily stored in the application memory and it does not get saved when the application is restarted.

One could argue that it should be possible to first decrypt the saved credentials with the existing key then re-encrypt with the new key, but the development team did not make that part of the software.

StackExchange Database Administrators Q#298886, answer score: 6