The Improved Include Page WordPress plugin through 1.2 allows passing shortcode attributes with post_type & post_status which can be used to retrieve arbitrary content. This way, users with a role as low as Contributor can gain access to content they are not supposed to.
[
{
"product": "Improved Include Page",
"vendor": "Unknown",
"versions": [
{
"lessThanOrEqual": "1.2",
"status": "affected",
"version": "1.2",
"versionType": "custom"
}
]
}
]