Discourse is an open source platform for community discussion. In affected versions an attacker can learn that a secret subcategory exists under a public category which has no public subcategories. The issue is patched in the latest stable, beta and tests-passed version of Discourse. Users are advised to upgrade. There are no known workarounds for this vulnerability.
{
    "cpes": [
        "cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*",
        "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*"
    ],
    "severity": "Medium"
}