Discourse Auth Bypass via publish_to_category Timer <=2025.12.2/2026.1.1/2026.2.0
CVE-2026-28227 Published on February 26, 2026
Discourse Vulnerable to Unauthorized Topic Creation in Staff-Only Categories via Topic Timer publish_to_category
Discourse is an open source discussion platform. Prior to versions 2025.12.2, 2026.1.1, and 2026.2.0, TL4 users can publish topics into staff-only categories via the `publish_to_category` topic timer, bypassing authorization checks. Versions 2025.12.2, 2026.1.1, and 2026.2.0 patch the issue. No known workarounds are available.
Weakness Type
What is an AuthZ Vulnerability?
The software performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions.
CVE-2026-28227 has been classified to as an AuthZ vulnerability or weakness.
Products Associated with CVE-2026-28227
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Affected Versions
discourse:- Version < 2025.12.2 is affected.
- Version >= 2026.1.0-latest, < 2026.1.1 is affected.
- Version >= 2026.2.0-latest, < 2026.2.0 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.