It's been well-established by now but owing to a discredited International Agency for Research on Cancer claim, which environmental groups insist remains valid despite finding that a member of the Working Group had financial conflicts of interest (consulting for environmental groups) and signed an agreement with a litigation attorney before the claims were made public, concern has persisted.

Using data from the Agricultural Health Study (AHS), scholars debunked claims of links between applications of plant protection products containing glyphosate and the occurrence of cancer. This applied to cancers in general, as well as to special cancer types, such as non-Hodgkin lymphoma, which activists have hoped to link with the glyphosate assessment. Claims of a possible association with acute myeloid leukaemia (AML) were also not real but it is expected that organic industry front groups like US Right To Know will insist they are important.

So how did IARC create a finding that was so flawed? They intentionally excluded the Agricultural Health Study, even though data had an additional 11 years. 

There are other vague claims that are still making their way around the Internet. One California academic with multiple conflicts of interest hoped to link pesticides to autism. But concerns about glyphosate and cancer are not on a fuzzy spectrum and so much easier to debunk. Unless people really want to believe them.