Hugo before 0.166.0 Cross-Site Scripting via text/org

Hugo is a static site generator. In versions from v0.56.0 through v0.165.x, content files mapped to the text/org media type are rendered without escaping raw HTML: Org export blocks and @@html:...@@ snippets pass HTML through unescaped, resulting in cross-site scripting (XSS) in the generated site. An attacker who can supply or influence a content file under /content or the output of a content adapter can inject scripts that execute in the browsers of visitors to the affected pages. Only pages whose source file or content-adapter output declares the text/org media type are affected, and sites that fully trust all content sources are not impacted. Version v0.166.0 fixes the issue by introducing a security.allowContent allowlist that denies text/org by default; sites that intentionally author Org Mode content can opt back in with [security] allowContent = ['.*'].