Medium severity · published Mar 20, 2026
CVE-2026-33425
Discourse has inferable private group membership or existence via exclude_groups parameter
5.3
CVSS
0.7%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 52% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DI
discourse · discourse
>= 2026.1.0-latest, < 2026.1.2; >= 2026.2.0-latest, < 2026.2.1; = 2026.3.0-latest · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-33425
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-33425
Mitigation
https://github.com/discourse/discourse/security/advisories/GHSA-r6rh-xvf5-r5f2
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