CVE-2026-33425: medium-severity vulnerability in discourse
Discourse has inferable private group membership or existence via exclude_groups parameter
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
28Vexday Risk Score
Patch soon. It has a working public exploit.
ssvc Attendcvss 6.9epss 0.7%
Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, unauthenticated users can determine whether a specific user is a member of a private group by observing changes in directory results when using the `exclude_groups` parameter. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, disable public access to the user directory via Admin → Settings → hide user profiles from public.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Affected products
discourse · discourseRelated CVEs — discourse
In the same product, most dangerous first.
CVE-2024-53991HIGHPotential Backup file leaked via Nginx in DiscourseEPSS 29.9%CVE-2021-41163CRITICALRCE via malicious SNS subscription payloadEPSS 19.8%CVE-2023-45131HIGHUnauthenticated access to new private chat messages in DiscourseEPSS 4.0%CVE-2026-28227LOWDiscourse Vulnerable to Unauthorized Topic Creation in Staff-Only Categories via Topic Timer publish_to_categoryEPSS 3.3%CVE-2022-36066CRITICALDiscourse vulnerable to RCE via admins uploading maliciously zipped fileEPSS 2.1%CVE-2024-47773HIGHAnonymous cache poisoning via XHR requests in DiscourseEPSS 1.8%