CVE-2026-31832 json
Umbraco Backoffice API Allows Unauthorized Modification of Domain Data
published 7mo ago modified 4mo ago also EUVD-2026-10934 , GHSA-fpvf-fvp5-996r
- cvss
- 5.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 11%
- public exploits
- 0
- none known
Summary
Umbraco is an ASP.NET CMS. From 14.0.0 to before 16.5.1 and 17.2.2, A broken object-level authorization vulnerability exists in a backoffice API endpoint that allows authenticated users to assign domain-related data to content nodes without proper authorization checks. The issue is caused by insufficient authorization enforcement on the affected API endpoint, whereby via an API call, domains can be set on content nodes that the editor does not have permission to access (either via user group privileges or start nodes). This vulnerability is fixed in 16.5.1 and 17.2.2.
Patch / fix
- nuget Umbraco.Cms 16.5.1, 17.2.2
- umbraco umbraco_cms 16.5.1, 17.2.0
Is CVE-2026-31832 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
- no
- Technical impact
- partial
- Assessed
- 7mo ago
Exploit prediction
0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L |
| GitHub | 3.1 | 5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| nuget | Umbraco.Cms | >=14.0.0, <16.5.1 >=17.0.0, <17.2.2 |
16.5.1 17.2.2 |
Affected products
- umbraco Umbraco-CMS
Classification
- Weakness
-
- CWE-639 Authorization Bypass Through User-Controlled Key
References
-
github.com
/umbraco/Umbraco-CMS/security/advisories/GHSA-fpvf-fvp5-996r
web, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-31832
advisory
-
github.com
/umbraco/Umbraco-CMS
package
Sources
- CVE List CVE-2026-31832
- GitHub Advisory GHSA-fpvf-fvp5-996r
- NVD CVE-2026-31832
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.