In vulnerable situation, ox shifted with speed (7)
I believe the answer is:
exposed
'in vulnerable situation' is the definition.
'ox shifted with speed' is the wordplay.
'shifted with' indicates an anagram.
'ox' anagrammed with 'speed' makes 'EXPOSED'.
(Other definitions for exposed that I've seen before include "Laid bare" , "vulnerable" , "Deprived of protection" , "Made public" , "at mercy of weather" .)