GHCi, version 6.12.3: http://www.haskell.org/ghc/ Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package ffi-1.0 ... linking ... done. 120000000000 Prelude> read "12e1000000000000" :: Integer Segmentation fault

Sometimes it fails with Bus error.

According to Haskell'98 and Haskell'00 Reports Integers should not parse exponential notation at all.

http://www.haskell.org/onlinereport/haskell2010/haskellch2.html\#x7-190002.5

This is security issue in web frameworks as parsing HTTP headers, URLs, JSON and other may involve parsing integers.