Auth bypass in Discourse
CVE-2026-28282
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.
Vulnerability class: Broken Access Control
EPSS: 0.003 (25.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Discourse — versions = 2026.3.0-latest, >= 2026.2.0-latest, < 2026.2.1, >= 2026.1.0-latest, < 2026.1.2
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-28282?
- CVE-2026-28282 is a medium-severity vulnerability in Discourse, classified under Incorrect Authorization. CVSS score: 6.5/10. Published 2026-03-19.
- How severe is CVE-2026-28282?
- Medium severity. CVSS v3 base score is 6.5 out of 10.