Forest looked set to suffer a first defeat on Teesside in 38 years when Scott McDonald fired the hosts ahead in the 51st minute.
Goalkeeper Lee Camp pulled off a series of fine saves to keep the visitors in the game, however, and his efforts were rewarded in the 92nd minute as Adebola pounced on a loose ball to scramble the ball past Jason Steele from eight yards.
Forest move up to fourth in the Championship table as a result and now sit three points behind second-placed Swansea.
Boro, meanwhile, remain 20th and will wonder how they failed to convert a much-improved second-half display into three points.
Jonathan Grounds replaced the injured Andrew Davies in the home side's defence, while Marvin Emnes dropped to the bench to accommodate the return of midfielder Barry Robson, who captained the side.
Forest boss Billy Davies also made two changes, with Garath McCleary and Robert Earnshaw coming in for Paul Anderson and Radoslaw Majewski.
Earnshaw saw an early effort fly wide before Middlesbrough tested Camp twice within the space of 30 seconds in the 10th minute. Julio Arca's powerful 20-yard strike was beaten away by the 26-year-old keeper, who then saved comfortably after Robson had tried his luck from a similar position.
David McGoldrick forced Steele into action soon after and centre-half Luke Chambers volleyed over from Chris Cohen's free-kick as the visitors looked to settle into their stride.
Clear-cut chances were in short supply as the half wore on, however, with both sides lacking a cutting edge in the final third.
Forest were forced into a change in the 38th minute when left-back Joel Lynch picked up an injury and was replaced by Brendon Moloney.
Middlesbrough's Andrew Taylor livened up proceedings moments later with a stinging drive from the edge of the box, but Camp reacted well to palm the ball behind for a corner.
The highly-rated stopper made another fine save from Tony McMahon's curling free-kick early in the second half and also denied Leroy Lita from 12 yards.
Yet Boro soon gained reward for their pressure as McDonald fired home his eighth goal of the season, the Australian finishing coolly at the back post after Arca had failed to connect cleanly with Robson's right-wing cross.
McDonald almost added a second in the 64th minute following Lita's flick-on and Taylor stung the palms of Camp once again with another thunderous left-footed shot.
Camp blocked a third effort from Taylor 11 minutes later, while Forest saw appeals for a penalty turned down when Arca blocked Chris Gunter's cross amid shouts for handball.
Robson looked to have added a second for Boro in the closing stages, but his deflected effort clipped the outside of the post.
Forest then snatched a somewhat fortuitous point as substitute Adebola, on for McGoldrick, levelled with seconds remaining.