A Regular Expression Denial of Service (ReDoS) issue was discovered in the sanitize_html function of redcloth gem v4.0.0. This vulnerability allows attackers to cause a Denial of Service (DoS) via supplying a crafted payload.
RedCloth Gem for Ruby contains a flaw that allows a cross-site scripting (XSS) attack. This flaw exists because the program does not validate input when parsing textile links before returning it to users. This may allow a remote attacker to create a specially crafted request that would execute arbitrary script code in a user's browser session within the trust relationship between their browser and the server.