Is there a noun meaning: person who accepts bribes?

Purchasable:

• Capable of being bribed; venal: a purchasable senator.

or

Corruptible:

• Capable of being corrupted: corruptible judges.

The Free Dictionsty

The appropriate word is venal, meaning bribable from the Latin venalis, sale. The venal politician is one whose influence is literally for sale.

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:

subvertible

subvert

(by extension)

: undermine or corrupt, as in morals

Origin of subvert Middle English subverten ; from Middle French subvertir ; from Classical Latin subvertere ; from sub-, sub- + vertere, to turn: see verse [Your Dictionary]l(http://www.yourdictionary.com/subvert#yHLbGASEEHAHtsIw.99)

: to pervert or corrupt by an undermining of morals, allegiance, or faith M-W

tamperable

tamper

: to use corrupt practices such as bribery or blackmail

: (usually followed by with) to attempt to influence or corrupt, esp by bribery: to tamper with the jury Collins English Dictionary

What's wrong with just "corrupt"?

Venal is those who accepts money in exchange of secret service .It is broadly used to describe corruption .But ,I will point out here ,Bribe is broader it may be used many dimensions. Money is also form of bribe so are other services. So ,Venal can be used ,given the context should also be considered.