Kubica, 32, will take part in a two-day tyre test along with Russian Sergey Sirotkin as the British-based team determine their line-up for 2018.
Alonso's team-mate Stoffel Vandoorne also enjoyed his best finish of the season, coming home 10th to add a point as the team bagged nine towards their championship haul.
Hungarian Grand Prix: Kevin Magnussen tells Nico Hulkenberg to 's**k my b***s' in ugly post-race clash
Hulkenberg broke into Magnussen's interview to praise him ironically as "once again the most unsporting driver", following an on-track clash during the race.
Hungarian Grand Prix: Max Verstappen apologises to Red Bull team-mate Daniel Ricciardo after 'amateur' crash
Max Verstappen crashed into Daniel Ricciardo's car at Turn Two where the impact caused damage that ended his race.
Hungarian Grand Prix: Lewis Hamilton hopes late swap with Valtteri Bottas won't cost him championship
Hamilton was given third place during the race when Finn Bottas, obeying a team request, allowed him by to launch an attack on the two Ferraris ahead.
Hungarian Grand Prix: Sebastian Vettel leads dominant Ferrari one-two, Lewis Hamilton finishes fourth
In his 50th race for Ferrari, Vettel controlled the contest from pole position in stifling heat to reel off his first win in five races since the Monaco Grand Prix.
Hungarian Grand Prix: Sebastian Vettel could extend lead over Lewis Hamilton after taking pole on tricky circuit
The 70-lap Hungarian GP, where aero and downforce come at a premium, demands driver skill like few other races. But Ferrari wouldn't mind the fact that the new-found pace and balance in their cars gives them quite a head-start on Sunday.
Hungarian Grand Prix: Daniil Kvyat on brink of race ban after impeding Lance Stroll during qualifying
The penalty increases Kvyat's tally to 10 in the last 12 months and leaves him within two points of a one-race ban.
Hungarian Grand Prix: Sebastian Vettel delighted to prove Ferrari's critics wrong with 'phenomenal' performance
Vettel praised the “phenomenal” performance of his car and team and added that it came after criticism following the British Grand Prix two weeks ago.