Disclose, expose, and divulge all refer to making something known or visible, yet these words have important differences.
Disclose means to reveal something, usually a factual matter, to the public that was previously kept secret, e.g.
“The seller failed to disclose hidden defects in the foundation of the house.”
Expose implies scandal, e.g. expose corruption, danger, e.g. expose to liability, or nakedness, e.g.
“The pedophile exposed himself to children in the park.”
Divulge means making known very private, deeply sensitive information, e.g. divulging state secrets.