The Penguin translation of the History of Alexander the Great by Q. Curtius Rufus tells me that there are 123 manuscripts of this work. A list is apparently given by Dosson in his Etude sur Quinte Curce, 1887, p.315-356 (online here).
The work was originally in 10 books, but books 1 and 2 are lost. There are also large lacunae at the end of book 5 / start of book 6, and in the middle of book 10. All the extant mss. are of French origin. The extant manuscripts, which date from the 9th century onwards, divide into two classes, one of which exhibits signs of scholarly tampering. There is also a mass of late mss, virtually unexamined.
Interestingly the work of Quintus Curtius Rufus is not referenced by other extant writers until the 9th century, although passages which suggest the author had read Curtius Rufus — or perhaps his source — can be found in Seneca, Lucan, and Quintilian.