Nunjucks is a full featured templating engine for JavaScript. Versions 2.4.2 and lower have a cross site scripting (XSS) vulnerability in autoescape mode. In autoescape mode, all template vars should automatically be escaped. By using an array for the keys, such as name[]=<script>alert(1)</script>
, it is possible to bypass autoescaping and inject content into the DOM.
[
{
"product": "nunjucks node module",
"vendor": "HackerOne",
"versions": [
{
"status": "affected",
"version": "<=2.4.2"
}
]
}
]