[5] The song features a "moody synth groove",[6] a "chugging rhythm",[5] and vocoded vocals[5] with a "ghostly edge".
[5] In terms of music notation, "Vulnerable" was composed using common time in the key of G minor, with a tempo of 100 beats per minute.
[7] Lyrically, it finds Gomez struggling to let someone in, through the chorus "if I show you all my demons/and we dive into the deep end/would we crash and burn like every time before?
Quinn Moreland of Pitchfork called the song Gomez's "best performance" stating that she "sounds firm and assured even when she dips into a whisper.
[10] Mike Wass from the website wrote that "Vulnerable" ranks "as one of best synth-pop offerings of 2020", calling it as "frighteningly addictive" as "musical heroin".