In FreeType before 2.6.1, a buffer over-read occurs in type1/t1parse.c on function T1_Get_Private_Dict where there is no check that the new values of cur and limit are sensible before going to Again.
https://support.f5.com/csp/article/K38315305?utm_source=f5support&%3Butm_medium=RSS
https://support.f5.com/csp/article/K38315305
https://lists.debian.org/debian-lts-announce/2019/08/msg00019.html