Consider something as simple as bribable:
bribable: open to improper influence and especially bribery
Example: corruption in that country is so widespread that there are few public officials who are not bribable
(M-W)
bribable: capable of being bribed
(Webster's Unabridged)
If you need a popular word that any Anglophone understands, I suggest corrupt:
Venal or dishonest
a corrupt mayor.
(American Heritage Dictionary)
I like "venal" very much (was about to post it myself), but I'm not sure how many native speakers are familiar with it. So it depends on the target audience. For what it's worth, here's an Ngram demonstrating the popularity of "venal" vs "corrupt" vs other options:
