Describe CVE-2018-12911.
What is CVE-2018-12911?
WebKitGTK+ 2.20.3 has an off-by-one error, with a resultant out-of-bounds write, in the get_simple_globs functions in ThirdParty/xdgmime/src/xdgmimecache.c and ThirdParty/xdgmime/src/xdgmimeglob.c..