The Time Warner-owned (TWC) cable network experienced a data breach that resulted in upcoming episodes and a possible script of HBO’s various television shows being leaked online, according to a report Monday by Entertainment Weekly.

“HBO recently experienced a cyber incident, which resulted in the compromise of proprietary information,” HBO told Entertainment Weekly in a statement. “We immediately began investigating the incident and are working with law enforcement and outside cybersecurity firms. Data protection is a top priority at HBO, and we take seriously our responsibility to protect the data we hold.”

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It’s unclear when and how the data breach occurred, and if any customer data was compromised.

HBO did not specify any digital materials hackers may have obtained through the data breach, but Entertainment Weekly reported that cyber criminals have stolen 1.5 terabytes of data. Among the compromised data are two upcoming episodes of Ballers, starring Dwayne “The Rock” Johnson, and Room 104.

HBO’s popular Game of Thrones show may have also been impacted, with hackers claiming to have obtained “written material” from the upcoming fourth episode from the fantasy drama’s latest season, the report said.

As the Guardian notes, unspecified hackers sent reporters an anonymous email on Sunday in which they bragged about breaching HBO.

“The greatest leak of cyber space era is happening,” the hackers wrote. “What’s its name? Oh I forget to tell. Its HBO and Game of Thrones……!!!!!!

Fortune contacted HBO for more information and will update this story if needed.