CVE-2026-33425 MEDIUM

CVE-2026-33425: Discourse has inferable private group membership or existence via exclude_groups parameter

Vendor Discourse
Product discourse
Weakness CWE-203
Published March 20, 2026
Last update March 23, 2026

CVSS base score

6.9/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 20, 2026 CVE published
March 23, 2026 Record updated