Improper access control in Discourse - CVE-2026-28282
Published: July 1, 2026
Vulnerability identifier: #VU136162
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-28282
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Civilized Discourse Construction Kit, Inc.
Affected software:
Discourse
Discourse
Detailed vulnerability description
The vulnerability allows a remote user to disclose sensitive information.
The vulnerability exists due to improper access control in the discourse-policy plugin when processing policies with the add-users-to-group attribute. A remote user can create a policy that adds themselves to a private or restricted group to disclose sensitive information.
Successful exploitation allows access to private topics restricted to the affected group.
How to mitigate CVE-2026-28282
Install security update from vendor's website.