Information disclosure in Discourse

CVE-2026-33300

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.

Vulnerability class: Information Disclosure

EPSS: 0.002 (14.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

Affected products

  • Discourse — versions >= 2026.3.0-latest, < 2026.3.0, >= 2026.2.0-latest, < 2026.2.2, >= 2026.1.0-latest, < 2026.1.3

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-33300?
CVE-2026-33300 is a medium-severity vulnerability in Discourse, classified under Information Disclosure. CVSS score: 6.5/10. Published 2026-03-31.
How severe is CVE-2026-33300?
Medium severity. CVSS v3 base score is 6.5 out of 10.