In 2018, she was given the longest prison sentence ever imposed for an unauthorized release of government information to the media[7] after she leaked an intelligence report about Russian interference in the 2016 United States elections.

[9] On June 3, 2017, while employed by the military contractor Pluribus International Corporation, Winner was arrested on suspicion of leaking an intelligence report about Russian interference in the 2016 United States elections from the National Security Agency (NSA) to the news website The Intercept.

The report indicated that Russian hackers accessed voter registration rolls in the United States with an email phishing operation,[10] though it was unclear whether any changes had been made.

[12] On August 23, 2018, Winner was convicted of "removing classified material from a government facility and mailing it to a news outlet" and sentenced to five years and three months in prison as part of a plea deal.

[19] Her father's influence early in her life had extensively shaped Winner's world view on many topics, including politics, history, philosophy, and religion.

[18] Winner served in the United States Air Force from 2010 to 2016, achieving the rank of senior airman (an E-4 paygrade) with the 94th Intelligence Squadron.

"[23] A month after being honorably discharged from the Air Force in November 2016, Winner moved to Augusta, Georgia, where she taught at a CrossFit gym and a yoga studio.

[18] Assigned to translate documents relating to Iran's aerospace program in Persian,[18] Winner was employed by Pluribus International Corporation at the time of her arrest.

[30] Winner told CBS's 60 Minutes that she leaked the classified material because she thought Americans were being intentionally misled about Russia's active measures to influence the outcome of the 2016 United States presidential election.

"[41] An internal review conducted by The Intercept into its handling of the document provided by Winner found that its "practices fell short of the standards to which we hold ourselves".

[38][45] Justice Department lawyers also argued that her defense team should not be allowed to discuss any classified information, even if it was in news reports published by the media.

"[38] Federal agents had found her diary during a search of her home, in which she allegedly expressed support for Taliban leaders and Osama bin Laden, and for burning down the White House.

[50] In December 2017, The Intercept reported that Winner's defense team was allowed to discuss the case with her, including its classified aspects, in a Sensitive Compartmented Information Facility (SCIF).

[64] On August 31, Winner said that she would ask Trump for clemency as a result of his tweet, adding that her legal team was already working on her pardon application.

[66] On April 24, 2020, a federal judge rejected Winner's request to commute the remaining 19 months of her 63-month sentence and be released to home confinement due to the COVID-19 pandemic.

[67] Winner's lawyer argued that her history of respiratory illness and immune system compromised by bulimia makes her highly vulnerable to the virus.

"[68] The judge found that Winner did not exhaust her administrative remedies through the BOP, which he held has sole authority to grant her compassionate release.

[53] On June 2, 2021, Winner was transferred from prison to a transitional facility,[70] the San Antonio, Texas, Residential Reentry Management center.

[71] According to Alison Grinter Allen, Winner's lawyer, she left prison early as a result of "good behavior" while inside, and not because of compassionate release.

[83] On May 29, 2023, HBO released Reality, a film adaptation of Is This A Room, starring Sydney Sweeney as Winner alongside Josh Hamilton and Marchánt Davis.