Adding new features is more fun than fixing bugs. Sadly we can't be fun here.
Mature teams prioritize bugs this way:
You have to fix stability before you add new features. Security issues are high priority stability issues.
One of the principles promoted by Mark Burgess is "seek stability, then new features". Some changes we make add features while others improve stability. The order should be feature, stability, feature, stability, feature, stability. Not feature, feature, feature, OMG!, stability, stability, stability. Make things stable before proceeding to the next awesome feature.
Doctors understand this. In a hospital emergency room a patient is stabilized first. You don't help someone recover from the flu if they are bleeding to death.
The priority of "performance bugs" is up for debate. In some places performance is the same as stability.
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