be hoist/hoisted by/with your own petard

hoist by/with (one's) own petard

To be injured, ruined, or defeated by one's own action, device, or plot that was intended to harm another; to have fallen victim to one's own trap or schemes. ("Hoist" in this instance is the past participle of the archaic form of the verb "hoise.") I tried to get my boss fired by planting drugs on him, but I was hoist by my own petard when the police caught me with them beforehand.
See also: by, hoist, own, petard
Farlex Dictionary of Idioms.

be hoist/hoisted by/with your own peˈtard

(British English) be caught in the trap that you were preparing for another personThis is from Shakespeare’s play Hamlet. A petard was a small bomb.
See also: by, hoist, own, petard
Farlex Partner Idioms Dictionary
See also:
  • be hoist by (one's) own petard
  • be hoist with (one's) own petard
  • be hoist with one's own petard
  • at will
  • about (one's) business
  • about business
  • be on (one's) pat
  • at the end of (one's) fingertips
  • be remembered for (something)
  • at (one's) doorstep