Bottle before 0.12.20 mishandles errors during early request binding.
bottle.py is a fast and simple micro-framework for python web-applications. redirect() in bottle.py in bottle 0.12.10 doesn't filter a "\r\n" sequence, which leads to a CRLF attack, as demonstrated by a redirect("233\r\nSet-Cookie: name=salt") call.
Bottle 0.10.x before 0.10.12, 0.11.x before 0.11.7, and 0.12.x before 0.12.6 does not properly limit content types, which allows remote attackers to bypass intended access restrictions via an accepted Content-Type followed by a ; (semi-colon) and a Content-Type that would not be accepted, as demonstrated in YouCompleteMe to execute arbitrary code.