CVE-2026-28282

Summary

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.

Impact & exploitability

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected products we track (1)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://github.com/discourse/discourse/commit/64e2514ac17046cfaa8bc68a3c5140bc40736add ↗

Additional information

• NVD record
• https://github.com/discourse/discourse/commit/64e2514ac17046cfaa8bc68a3c5140bc40736addPatch
• https://github.com/discourse/discourse/commit/c14b8a4cc5fc94e4839a83c5d55765897589f45bPatch
• https://github.com/discourse/discourse/commit/dcde9de530f515e88f99957056ffbcc2e1e03951Patch
• https://github.com/discourse/discourse/security/advisories/GHSA-6cc8-x3rm-j5pfAdvisory