CVE-2026-49256 json
Discourse: Hidden tag names leaked via category serializers
published 2026-07-09 4 mo ago modified 2026-09-10 59 d ago also BIT-discourse-2026-49256 , EUVD-2026-42730 , GHSA-mwp7-572g-6qpx
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 43%
- public exploits
- 0
- none known
Summary
Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, restricted tag and tag-group names attached to publicly readable categories as allowed_tags, allowed_tag_groups, or required tag groups could leak to anonymous and unauthorized users through category and group endpoints. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
Patch / fix
- bitnami discourse 2026.1.5, 2026.4.2, 2026.5.1
- discourse discourse 2026.1.5, 2026.4.2, 2026.5.1
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.3 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N |
| CNA | 4.0 | 6.3 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/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 |
| OSV | 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, <2026.1.5 >=2026.4.0, <2026.4.2 >=2026.5.0, <2026.5.1 |
2026.1.5 2026.4.2 2026.5.1 |
Affected products
- discourse discourse
Classification
- Weakness
-
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
References
-
github.com
/discourse/discourse/releases/tag/v2026.1.5
release-notes, patch
-
github.com
/discourse/discourse/security/advisories/GHSA-mwp7-572g-6qpx
vendor-advisory, mitigation, advisory
-
github.com
/discourse/discourse/releases/tag/v2026.4.2
release-notes, article
-
github.com
/discourse/discourse/releases/tag/v2026.5.1
release-notes, article
-
github.com
/discourse/discourse/releases/tag/v2026.6.0
release-notes, article
-
nvd.nist.gov
/vuln/detail/CVE-2026-49256
web
Sources
- CVE List CVE-2026-49256
- NVD CVE-2026-49256
- OSV BIT-discourse-2026-49256
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.