Hugo is a static site generator. Starting in version 0.123.0 and prior to version 0.139.4, some HTML attributes in Markdown in the internal templates listed below not escaped in internal render hooks. Those whoa re impacted are Hugo users who do not trust their Markdown content files and are using one or more of these templates: `_default/_markup/render-link.html` from `v0.123.0`; `_default/_markup/render-image.html` from `v0.123.0`; `_default/_markup/render-table.html` from `v0.134.0`; and/or `shortcodes/youtube.html` from `v0.125.0`. This issue is patched in v0.139.4. As a workaround, one may replace an affected component with user defined templates or disable the internal templates.
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.