MD5:
In 1996, a flaw was found with the design of MD5, and while it was
not a clearly fatal weakness, cryptographers began recommending the
use of other algorithms, such as SHA-1—which has since been found to
be vulnerable as well.
SHA1:
In 2005, cryptanalysts found attacks on SHA-1 suggesting that the
algorithm might not be secure enough for ongoing use
SHA2 which SHA256 is a type of does not have a known vulnerability as of the moment of writing.
