The kramdown gem before 2.3.0 for Ruby processes the template option inside Kramdown documents by default, which allows unintended read access (such as template="/etc/passwd") or unintended embedded Ruby code execution (such as a string that begins with template="string://<%= `). NOTE: kramdown is used in Jekyll, GitLab Pages, GitHub Pages, and Thredded Forum.
{ "nvd_published_at": "2020-07-17T16:15:00Z", "cwe_ids": [ "CWE-862" ], "severity": "CRITICAL", "github_reviewed": true, "github_reviewed_at": "2020-08-07T22:27:22Z" }