CVE-2026-28227
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2026-28227- CVSS 4.0
- 1.2 Low
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 - Weakness
- CWE-863
- Updated
- 2026-11-02
EUVDEUVD-2026-8901
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.
- Record
EUVD-2026-8901- CVSS 4.0
- 1.2 Low
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 - Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-28227- CVSS 4.0
- 1.2 Low
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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 2.7 Low
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N - Weakness
- CWE-863
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2026-28227- CVSS 4.0
- 1.2 Low
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 - Weakness
- CWE-863
- Updated
- 2026-11-02
OSVBIT-discourse-2026-28227No score
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.
- Record
BIT-discourse-2026-28227- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
discourseBitnami | before 2025.12.2, 2026.1.0 up to 2026.1.1 | 2025.12.22026.1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-28227 is a low vulnerability (CVSS 1.2) in Discourse, published February 26, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.23%, the 88th percentile. Fixed in discourse 2025.12.2.