LINE client for iOS before 11.15.0 might expose authentication information for a certain service to external entities under certain conditions. This is usually impossible, but in combination with a server-side bug, attackers could get this information.
Integer overflow vulnerability in LINE(Android) from 4.4.0 to the version before 9.15.1 allows remote attackers to cause a denial of service (DoS) condition or execute arbitrary code via a specially crafted image.