Vulnerabilities

Highlight.js is a syntax highlighter written in JavaScript. Highlight.js versions before 9.18.2 and 10.1.2 are vulnerable to Prototype Pollution. A malicious HTML code block can be crafted that will result in prototype pollution of the base object's prototype during highlighting. If you allow users to insert custom HTML code blocks into your page/app via parsing Markdown code blocks (or similar) and do not filter the language names the user can provide you may be vulnerable. The pollution should just be harmless data but this can cause problems for applications not expecting these properties to exist and can result in strange behavior or application crashes, i.e. a potential DOS vector. If your website or application does not render user provided data it should be unaffected. Versions 9.18.2 and 10.1.2 and newer include fixes for this vulnerability. If you are using version 7 or 8 you are encouraged to upgrade to a newer release.

This affects the package markdown-it-highlightjs before 3.3.1. It is possible insert malicious JavaScript as a value of lang in the markdown-it-highlightjs Inline code highlighting feature. const markdownItHighlightjs = require("markdown-it-highlightjs"); const md = require('markdown-it'); const reuslt_xss = md() .use(markdownItHighlightjs, { inline: true }) .render('console.log(42){.">js}'); console.log(reuslt_xss);

An issue was discovered in the wp-code-highlightjs plugin through 0.6.2 for WordPress. wp-admin/options-general.php?page=wp-code-highlight-js allows CSRF, as demonstrated by an XSS payload in the hljs_additional_css parameter.