According to the NYT, a Hamas-sourced document codenamed "Jericho Wall" was somehow made public. It described in a fair bit of detail how the Hamas attack on Oct 7 eventually unfolded. (In response to one comment: note that the name/title of the document was definitely set by Israelis though, according to NYT.)
Israeli officials obtained Hamas’s battle plan for the Oct. 7 terrorist attack more than a year before it happened, documents, emails and interviews show. But Israeli military and intelligence officials dismissed the plan as aspirational, considering it too difficult for Hamas to carry out.
The approximately 40-page document, which the Israeli authorities code-named “Jericho Wall,” outlined, point by point, exactly the kind of devastating invasion that led to the deaths of about 1,200 people. The translated document, which was reviewed by The New York Times, did not set a date for the attack, but described a methodical assault designed to overwhelm the fortifications around the Gaza Strip, take over Israeli cities and storm key military bases, including a division headquarters. Hamas followed the blueprint with shocking precision. The document called for a barrage of rockets at the outset of the attack, drones to knock out the security cameras and automated machine guns along the border, and gunmen to pour into Israel en masse in paragliders, on motorcycles and on foot — all of which happened on Oct. 7. [...]
The document circulated widely among Israeli military and intelligence leaders, but experts determined that an attack of that scale and ambition was beyond Hamas’s capabilities, according to documents and officials. It is unclear whether Prime Minister Benjamin Netanyahu or other top political leaders saw the document, as well.
[... Israeli] Officials would not say how they obtained the Jericho Wall document, but it was among several versions of attack plans collected over the years.
What's unclear to me is: who made this document public in Israel? Was it a leak or did some Israeli authority decide to officially release it to the public, and if so when was it released (or leaked)?
FWTW, a later Politico article says that US officials deny having ever seen the "Jericho Wall" document before, so implicitly they also seem to deny they leaked or released it.