What words have the same vowel sound as success?

The U has an unstressed schwa sound (but is the same sound as the short U in such and suck) and the E has a short E sound.

The schwa-U is seen in buffoon and summation.

The short E (as in dress and mess)can be made by several spellings:

E Words - red, men, end, ebb, edit

EA Words - bread, deaf, death, health, sweat

UE Words - guess, guest

A Words - many, can, says

U Words - bury

AI Words - said, again