Uber representatives did not immediately respond to an email seeking comment.
Along with over dozens of sexual harassment cases the report also included instances where Kalanick took his employees to a karaoke-escort bar when they visited Seoul in 2014.
The recommendations follow an investigation undertaken by Holder and his legal partner, Tammy Albarrán - of the law firm Covington & Burling LLP - who were asked by Uber to investigate claims of sexual harassment in the company.
The San Francisco-based ride-hailing service has more than 12,000 employees. Ever since 2009, Kalanick has worked endlessly to make Uber what it is now, a near $70 billion entity.
But Kalanick has acknowledged his management style needs improvement. In the aftermath he said "I must fundamentally change as a leader and grow up".
The review came after former Uber engineer Susan Fowler made claims of sexual harassment against her manager. Law firm Perkins Coie also conducted a separate investigation into the company focusing on similar concerns. The executive told Buzzfeed in November that Uber was considering digging into reporters' personal lives and families to stem negative coverage of the company.
The former employee said Uber suffered from a chaotic companywide culture of sexism and unprofessional business practices that had serious work-flow consequences, including the abandonment of projects and altered objectives. But Huffington, a founder of Huffington Post, suggested time might be running out. Kalanick's father was seriously injured.
On Sunday, it also came to light that embattled CEO Travis Kalanick could be taking a three-month leave of absence.
She is the third high-profile female appointment to the company in the past week. In March, Uber's president, Jeff Jones, resigned after less than a year on the job.
It isn't clear what the details of Holder's report will contain or what actions the Uber board might take today, but the moment is shaping up as a critical one for Uber's future. Previously, Saint John worked as head of global consumer marketing for Apple.