CVE-2026-28282 LOW

CVE-2026-28282: Discourse vulnerable to group membership addition permission bypass via discourse-policy plugin

Vendor Discourse
Product discourse
Weakness CWE-863 · Incorrect authorization
Published March 19, 2026
Last update March 20, 2026

CVSS base score

2.3/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 have a security flaw in the discourse-policy plugin which allowed a user with policy creation permission to gain membership access to any private/restricted groups. Once membership to a private/restricted group has been obtained, the user will be able to read private topics that only the group has access to. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, review all policies for the use of `add-users-to-group` and temporarily remove the attribute from the policy. Alternatively, disable the discourse-policy plugin by disabling the `policy_enabled` site setting.

Key dates

02Disclosure timeline

March 19, 2026 CVE published
March 20, 2026 Record updated