CVE-2026-28227

Discourse Vulnerable to Unauthorized Topic Creation in Staff-Only Categories via Topic Timer publish_to_category

Published Feb 26, 2026 CVSS 4.0 · 1.2 Low EPSS 3.2% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
CPEs cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*
cpe:2.3:a:discourse:discourse:2026.2.0:*:*:*:latest:*:*:*
Metrics cvssV3_1

{'score': 2.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N'}

Type Values Removed Values Added
First Time appeared Discourse
Discourse discourse
Vendors & Products Discourse
Discourse discourse
Type Values Removed Values Added
Description 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.
Title Discourse Vulnerable to Unauthorized Topic Creation in Staff-Only Categories via Topic Timer publish_to_category
Weaknesses CWE-863
References
Metrics cvssV4_0

{'score': 1.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Mar 3, 2026, 2:44 PM
Reserved
Feb 25, 2026, 3:28 PM
Status
Analyzed
Published
Feb 26, 2026, 10:20 PM
Modified
Jun 17, 2026, 10:28 AM