vncpasswd - TigerVNC
https://tigervnc.org/doc/vncpasswd.htmlThe password must be at least six characters long (unless the −f command-line option is used-- see below), and only the first eight characters are significant. Note that the stored password is not encrypted securely - anyone who has access to this file can trivially find out the plain-text password, so vncpasswd always sets appropriate permissions (read and write only by the …
TightVNC: Manual Page for vncpasswd(1)
https://www.tightvnc.com/vncpasswd.1.phpEach password has to be longer than five characters (unless the -f command-line option was used, see its description below). Only the first eight characters are significant. If the primary password is too short, the program will abort. If the view-only password is too short, then only the primary password will be saved.