CVE-2026-33300: Discourse

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, an authorization bypass in the Category Chatables Controller show action allowed moderators to get information on hidden groups names and user count. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.

Affected products

• Discourse Discourse: from 2026.1.0, before 2026.1.3 (fixed in 2026.1.3); from 2026.2.0, before 2026.2.2 (fixed in 2026.2.2); version 2026.3.0 only

Published 2026-03-31. Last modified 2026-07-24.