CVE-2026-28227 json
Discourse Vulnerable to Unauthorized Topic Creation in Staff-Only Categories via Topic Timer publish_to_category
published 8mo ago modified 2mo ago also BIT-discourse-2026-28227 , EUVD-2026-8901 , GHSA-m49w-78mh-87jp
- cvss
- 2.7
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 3.2%
- EPSS 3.2% chance of exploitation in 30 days, percentile 88%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- bitnami discourse 2025.12.2, 2026.1.1
- discourse discourse 2025.12.2, 2026.1.1, 2026.2.0
Is CVE-2026-28227 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 8mo ago
Exploit prediction
3.23% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 1.2 | 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 |
| CNA | 4.0 | 1.2 | 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 |
| NVD | 3.1 | 2.7 | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| bitnami | discourse | <2025.12.2 >=2026.1.0, <2026.1.1 |
2025.12.2 2026.1.1 |
Affected products
- discourse discourse
Classification
- Weakness
-
- CWE-863 Incorrect Authorization
References
-
github.com
/discourse/discourse/security/advisories/GHSA-m49w-78mh-87jp
vendor-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-28227
web
Sources
- CVE List CVE-2026-28227
- NVD CVE-2026-28227
- OSV BIT-discourse-2026-28227
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.