The Meta Box WordPress plugin before 5.9.4 does not prevent users with at least the contributor role from access arbitrary custom fields assigned to other user’s posts.
[
{
"vendor": "Unknown",
"product": "Meta Box ",
"versions": [
{
"status": "affected",
"versionType": "semver",
"version": "0",
"lessThan": "5.9.4"
}
],
"defaultStatus": "unaffected"
}
]