CVE-2026-27151 json
Discourse doesn't validate destination topic when moving posts
published 2026-02-26 8 mo ago modified 2026-09-08 2 mo ago also BIT-discourse-2026-27151 , EUVD-2026-8890 , GHSA-m69h-9m2g-cfgw
- cvss
- 2.7
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 7%
- 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, the `move_posts` action only checked `can_move_posts?` on the source topic but never validated write permissions on the destination topic. This allowed TL4 users and category group moderators to move posts into topics in categories where they lack posting privileges (e.g., read-only categories or categories with group-restricted write access). 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
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 8 mo ago
Exploit prediction
0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 1.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U |
| CNA | 4.0 | 1.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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-862 Missing Authorization
References
-
github.com
/discourse/discourse/security/advisories/GHSA-m69h-9m2g-cfgw
vendor-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-27151
web
Sources
- CVE List CVE-2026-27151
- NVD CVE-2026-27151
- OSV BIT-discourse-2026-27151
Fencer Vulns 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.