UEFA is "primarily responsible" for the "near-miss" at last year's Champions League final, where "the parallels between Hillsborough 1989 and Paris 2022" were "palpable".
Those findings from an independent review, commissioned by UEFA, were released on Monday after investigating incidents at the Stade de France showpiece between Liverpool and Real Madrid on May 28.
The report cited a lack of "Plan B when things went wrong" and concluded UEFA and French authorities were wrong to blame thousands of Liverpool supporters with "fake tickets" for the concerning ongoings.
French police were criticised for their treatment of fans, which included using tear gas, while demanding UEFA takes responsibility for issues, along with the French Football Federation and policing authorities.
"The dangerous conditions on the concourse outside the turnstiles were compounded by the police deploying tear gas at disorderly groups of locals, as well as using pepper spray on supporters trying to gain entrance with valid tickets," the report said.
"It is remarkable that no one lost their life. All the stakeholders interviewed by the panel have agreed that this situation was a near-miss: a term used when an event almost turns into a mass fatality catastrophe.
"The late change of venue meant that the normal timetable for organisation had to be truncated, and planning for the event had to be adapted to the circumstances.
"Compromises could be made to many areas of the event, but safety and security were not among them. Whereas there could be no bidding process or development of a concept, full attention should have been paid to the formulation and agreement of venue and event risk assessments, and proper operational plans. That did not happen.
"Senior officials at the top of UEFA allowed this to happen, even though the shortcomings of its model were widely known at senior management level, as acknowledged to the panel."
Comparisons were drawn by Liverpool supporters between Paris 2022 and the fatal Hillsborough events in 1989 in which 97 supporters died, with the report concurring that UEFA risked a repeat last year.
It added: "The parallels between Hillsborough 1989 and Paris 2022 are palpable. The similarities include the fact that both events were preventable, and both were caused by the failures of those responsible for public safety. Neither was a 'black swan' event, or the result of a 'perfect storm'."
Allegations ticketless Liverpool fans caused the issues outside the ground were found to be "wrongly inflated and exaggerated".
"The panel draws the inference that they have been made [ticketless fans claims] primarily to deflect from responsibility for planning and operational failures," the report added.
"This is reprehensible and has involved UEFA, UEFA Events SA, FFF, the Prefecture de Police, Government Officials and French Ministers.
"Both events were foreseeable. In the judgment of the panel, the different outcomes were a matter of chance: in one nearly a hundred died, the other none, but through no merit of those in charge."
The review expressed concerns lessons have not been learned, with France set to host the Rugby World Cup later this year, and questioned Michel Cadot, the French government official responsible for major sporting events.
"Despite Mr Cadot's willingness to accept that mistakes had been made [at the final], the panel is concerned that there remains a misconception about what actually happened and complacency regarding what needs to change," the report continued.
"This is particularly acute given the proximity of the Rugby World Cup and Olympic and Paralympic Games and the importance of the Stade de France to both events."
The report also made 21 recommendations for improvements, including for safety and security to be at the forefront of planning and matches to be managed with a "facilitation and service" approach towards supporters rather than viewing them as a potential public order problem.
UEFA promised to announce a "special refund scheme for fans" and said it was "currently analysing the findings of the review and assessing them against its own analysis of the organisation of the event and facts that occurred around it" after the review was released.