Juniper Networks QFX3500, QFX3600, QFX5100, QFX5200, EX4300 and EX4600 devices running Junos OS 14.1X53 prior to 14.1X53-D40, 15.1X53 prior to 15.1X53-D40, 15.1 prior to 15.1R2, do not pad Ethernet packets with zeros, and thus some packets can contain fragments of system memory or data from previous packets. This issue is also known as 'Etherleak'
https://kb.juniper.net/JSA10773