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.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
Present
Additional conditions required
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
Low
Partial data modification
Availability
None
No disruption
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products 3
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Discourse Discourse
cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*
|
2026.1.0
|
2026.1.2
|
|
Discourse Discourse
cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*
|
2026.2.0
|
2026.2.1
|
|
Discourse Discourse
cpe:2.3:a:discourse:discourse:2026.3.0:*:*:*:latest:*:*:*
|
— | — |
References 4
https://github.com/discourse/discourse/commit/64e2514ac17046cfaa8bc68a3c5140bc4…
security-advisories@github.com
https://github.com/discourse/discourse/commit/c14b8a4cc5fc94e4839a83c5d55765897…
security-advisories@github.com
https://github.com/discourse/discourse/commit/dcde9de530f515e88f99957056ffbcc2e…
security-advisories@github.com
https://github.com/discourse/discourse/security/advisories/GHSA-6cc8-x3rm-j5pf
security-advisories@github.com