CVE-2026-27934 json
Discourse leaks private topic title and post excerpt via user action API endpoint
published 2026-03-19 7 mo ago modified 2026-09-08 2 mo ago also BIT-discourse-2026-27934 , EUVD-2026-13196 , GHSA-824f-66wh-xx3g
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 68%
- public exploits
- 0
- none known, plus a Nuclei check
Summary
Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 have a lack of visibility checks with a user action API endpoint that results in disclosure of the title and post excerpt to unauthorized users, leading to information disclosure. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.
Patch / fix
- bitnami discourse 2026.1.2, 2026.2.1, 2026.3.0
- discourse discourse 2026.1.2, 2026.2.1
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 7 mo ago
Exploit prediction
1.22% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- Nuclei template Discourse < 2026.1.2/2026.2.1/2026.3.0-latest.1 - Unauthenticated Private User Action Disclosure nuclei detection template
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N |
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/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 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| bitnami | discourse | >=2026.1.0, <2026.1.2 >=2026.2.0, <2026.2.1 >=2026.3.0, <2026.3.0 |
2026.1.2 2026.2.1 2026.3.0 |
Affected products
- discourse discourse
Classification
- Weakness
-
- CWE-201 Insertion of Sensitive Information Into Sent Data
References
-
github.com
/discourse/discourse/security/advisories/GHSA-824f-66wh-xx3g
vendor-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-27934
web
Sources
- CVE List CVE-2026-27934
- NVD CVE-2026-27934
- OSV BIT-discourse-2026-27934
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.