Vulnerability · Published Mar 19, 2026 · Assigned by GitHub_M
CVE-2026-28282Discourse vulnerable to group membership addition permission bypass via discourse-policy plugin
Low 2.3
In plain English
A low-severity incorrect authorization in discourse from discourse. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities).
Official description
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.
Affected products (as reported)
Weakness: CWE-863 · 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
References
- https://github.com/discourse/discourse/security/advisories/GHSA-6cc8-x3rm-j5pf x_refsource_CONFIRM
- https://github.com/discourse/discourse/commit/64e2514ac17046cfaa8bc68a3c5140bc40736add x_refsource_MISC
- https://github.com/discourse/discourse/commit/c14b8a4cc5fc94e4839a83c5d55765897589f45b x_refsource_MISC
- https://github.com/discourse/discourse/commit/dcde9de530f515e88f99957056ffbcc2e1e03951 x_refsource_MISC