Which sounds oddly similar to the negative side effect of the Murituri process from the Marvel comic Strikeforce Morituri.
The story of the series was that in another universe Earth was attacked by a fleet of brutal aliens called the Horde. Eventualy a scientist perfects a method which can grant normal humans enhanced physical performance and random super powers.
However not only was the process only compatible with a small percentage of the human population (around 5%), but anyone who received it would eventualy die, most often via their super powers overcharging and going out of control.
Hence the title of the series, being based on the latin phrase: "moritūrī tē salūtant" = "those who are about to die salute you".
The world of Strikeforce Morituri or at least one like it actualy exist in the Marvel Multiverse. During Si Spurrier's X-force, an illegal arms dealer called Volga forced a mutant with the ability to jump between dimensions to steal various valuable technologies from alternative Earths including a "flesh printer" and the morituri process itself.
When Volga's scientists tested it in the 616 universe it turns out that while depowered mutants are seemingly perfect fits for the process (it basicly takes up the "empty spot" where their x-gene used to be), albeit still subjective to the "after one year go boom" problem, still powered mutants will explode after barely a day because of their powers overcharging.
Later in the series it's revealed that the scientist also found a way to stablize it (or insert a manual trigger mechanism if henchmen need to be disposed), which Doctor Nemesis then used to reverse engineer a similar cure for affected mutants like Cable.
Considering that the legacy virus was an artifical creation from Stryfe's future, it's weirdly possible that it might have it's origins in a similar flawed human empowering process.
Infact one can also draw similarities to the effect terrigen mist has on mutants.
Like how during the X-Cell story in PAD's X-factor, Quicksilver repowered a group of depowered mutants using the terrigen mist crystal he embeded in his body. However after a short while one of them exploded and the others were seemingly close to suffering the same fate aswell when they got teleported away into another dimension.