New research into attacks against the SHA-1 cryptographic algorithm lessen the cost and time to arrive at a practical collision. Bruce Schneier in 2012 projected that a collision attack would cost $700,000 by 2015, and $143,000 in 2018. New research suggests that a real collision could take between 49 and 78 days on a 512 GPU cluster. The CA/Browser Forum proposed a motion to allow the issuance of certificates through Dec. 31, 2016, in a motion taking place Oct. 2.
Source: https://threatpost.com/practical-sha-1-collision-months-not-years-away/114979/