RubyGems version Ruby 2.2 series: 2.2.9 and earlier, Ruby 2.3 series: 2.3.6 and earlier, Ruby 2.4 series: 2.4.3 and earlier, Ruby 2.5 series: 2.5.0 and earlier, prior to trunk revision 62422 contains a Improper Input Validation vulnerability in ruby gems specification homepage attribute that can result in a malicious gem could set an invalid homepage URL. This vulnerability appears to have been fixed in 2.7.6.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.