Evidence suggests that Albus Dumbledore could have an Obscurus as well in the Fantastic Beastsmovies. In 2018, David Yates' Fantastic Beasts: The Crimes Of Grindelwald introduced a younger Albus Dumbledore (Jude Law) into the Harry Potter franchise, and it's become clear that him and his family have become key parts of the Fantastic Beasts story arc.
As the second installment in the Fantastic Beasts series, Fantastic Beasts: The Crimes of Grindelwald was naturally filled with exposition and even contained some surprising connections to the overarching Harry Potter franchise, such as Ezra Miller's Credence Barebone being Ablus Dumbledore's brother. That twist came in Fantastic Beasts: The Crimes of Grindelwald's ending, and it could've been difficult to believe for some fans, which is why some fans believe it's possible Johnny Depp's Gellert Grindelwald lied to Credence about his Dumbledore connections.
In Harry Potter/Fantastic Beasts canon, an Obscurus is a dark, parasitic magical force that can develop in a witch or wizard if they are forced to consistently suppress their powers, usually due to shame and/or fear. By supressing their magical powers, a witch or wizard then becomes an Obscurial, and if they lose control, their Obscurus can be unleashed as a separate force; that force can wreak havoc around them, as shown in the first Fantastic Beasts movie. Obscurials are very rare and very dangerous, although it has been suggested that an Obscurial can be healed by working through the negative emotions that led to the development of their Obscurus in the first place.
In Fantastic Beasts And Where To Find Them, it was revealed that Credence Barebone is an Obscurial; he was raised by a woman with a hatred of magic, and he unwittingly let his Obscurus loose on New York. It seemed that this might've been the end to Credence's story, but the sequel, Fantastic Beasts: The Crimes Of Grindelwald, ended with a major twist. Credence and Grindelwald were holed up in Grindelwald's mountain home, which is where Grindelwald revealed Credence's real name - Aurelius Dumbledore. Furthermore, Grindelwald says that Credence/Aurelius is Albus Dumbledore's brother, and then gifts his young protégé with a wand, which he's able to use to create a spell of such force it takes out a chunk of the mountainside.
In the Harry Potter series, audiences learn that Dumbledore had a younger sister, who was kept hidden away from the wizarding world. At the age of six, she was set upon by a group of muggle boys who caught her doing magic (in the uncontrolled way that most magical children do), and was so emotionally scarred by the experience that she became too afraid to use her magical gifts. Instead, her magic "turned inwards" and began to explode out of her when she was upset or angry. In the end, these explosions ended up killing their mother, and eventually, Ariana herself was killed after becoming involved in a magical duel between Albus, their brother Aberforth, and Grindelwald.
Everything checks out for Ariana to have been an Obscurial too; magical power that was suppressed and twisted out of fear and trauma, and that power becoming unstable, uncontrollable, and bursting out of her when afraid or angry. This has led fans to question whether it's likely that there could be some kind of genetic component to the development of an Obscurus; if two people from one family (both Ariana and Aurelius) have developed this incredibly rare condition, might a third have it as well?