The commit 21c72ab introduced a regex (GIT_RE) to detect git-ssh URLs and corrected protocol assignment. Prior to this fix, URLs like 'git@github.com:user/repo.git' were parsed with protocol 'file' instead of 'ssh'. This misclassification could allow SSRF if applications used the parsed protocol/resource to make requests, as attackers could exploit the incorrect parsing to target internal systems. The vulnerability directly stems from the parsing logic in parseUrl, which was updated in the patch.