Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| discourse | discourse | >= 2026.1.0-latest, < 2026.1.2, >= 2026.2.0-latest, < 2026.2.1, = 2026.3.0-latest | — |
Automated scanner template
A ready-made Nuclei template detects this vulnerability automatically. Vulnerabilities with public scanner templates are typically probed across the internet soon after the template appears — exposed systems should be patched first.
- Discourse - Private Group Membership Inference via exclude_groups http/cves/2026/CVE-2026-33425.yaml
Source: projectdiscovery/nuclei-templates (MIT) — updated daily. Only links are listed.