We have broken SHA-1 in practice

https://link.springer.com/chapter/10.1007/978-3-319-63688-7_...

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"This result is the product of a long term collaboration between the Cryptology Group at Centrum Wiskunde & Informatica (CWI) - the national research institute for mathematics and computer science in the Netherlands - and the Google Research Security, Privacy and Anti-abuse Group. Two years ago Marc Stevens and Elie Bursztein, who leads the Google's anti-abuse research team, began collaborating on making Marc's cryptanalytic attacks against SHA-1 practical by leveraging Google expertise and infrastructure. Since then many CWI researchers and Googlers have helped make this project possible, including Pierre Karpman who worked on the cryptanalysis and prototype GPU implementation, and from Google Ange Albertini who developed the PDF attack, Yarik Markov who took care of the distributed GPU code, Alex Petit-Bianco implemented the collision detector to protect Google users, Luca Invernizzi who created the online file checker, and Clement Blaisse who oversaw the reliability of the computations."

https://www.cwi.nl/en/groups/cryptology/

Could Summit do it in a day?

https://en.wikipedia.org/wiki/Summit_(supercomputer)