CVE-2026-31832
Umbraco Backoffice API Allows Unauthorized Modification of Domain Data
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Umbraco Backoffice API Allows Unauthorized Modification of Domain Data
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.
- Record
CVE-2026-31832- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L - Weakness
- CWE-639
- Updated
- 2026-11-02
EUVDEUVD-2026-10934
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.
- Record
EUVD-2026-10934- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-fpvf-fvp5-996r
Umbraco Backoffice API Allows Unauthorized Modification of Domain Data
Description
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).
Impact
An attacker can modify domain configurations for content nodes they are not permitted to edit. This may result in malicious or unintended routing behaviour, service disruption, and potential disclosure of configuration-related information.
Patches
The issue is patched in 16.5.1 and 17.2.2.
Workarounds
There is no workaround other than upgrading.
- Record
GHSA-fpvf-fvp5-996r- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L - Weakness
- CWE-639
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-31832- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L - Weakness
- CWE-639
- Updated
- 2026-11-02
OSV
Umbraco Backoffice API Allows Unauthorized Modification of Domain Data
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.
- Record
CVE-2026-31832- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L - Weakness
- CWE-639
- Updated
- 2026-11-02
OSVGHSA-fpvf-fvp5-996r
Umbraco Backoffice API Allows Unauthorized Modification of Domain Data
Description
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).
Impact
An attacker can modify domain configurations for content nodes they are not permitted to edit. This may result in malicious or unintended routing behaviour, service disruption, and potential disclosure of configuration-related information.
Patches
The issue is patched in 16.5.1 and 17.2.2.
Workarounds
There is no workaround other than upgrading.
- Record
GHSA-fpvf-fvp5-996r- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L - Weakness
- CWE-639
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
Umbraco.CmsNuGet |
14.0.0 up to 16.5.1 | 16.5.1 |
Umbraco.CmsNuGet |
17.0.0 up to 17.2.2 | 17.2.2 |
Umbraco.CmsNuGet |
14.0.0 up to 16.5.1, plus listed versions 14.1.014.1.0-rc14.1.0-rc214.1.114.1.2 Show 45 moreShow less14.2.014.2.0-rc14.2.0-rc214.2.0-rc314.3.014.3.0-rc14.3.114.3.214.3.314.3.415.0.015.0.0-rc115.0.0-rc215.0.0-rc315.0.0-rc415.1.015.1.0-rc15.1.0-rc215.1.115.1.215.2.015.2.0-rc15.2.115.2.215.2.315.3.015.3.0-rc15.3.0-rc215.3.115.4.015.4.0-rc15.4.0-rc215.4.115.4.215.4.315.4.416.0.016.0.0-rc16.0.0-rc216.0.0-rc316.0.0-rc416.0.0-rc516.0.0-rc616.1.016.1.0-rc |
16.5.1 |
Umbraco.CmsNuGet |
17.0.0 up to 17.2.2, plus listed versions 17.0.117.0.217.1.017.1.0-rc17.2.017.2.0-rc17.2.0-rc217.2.1 |
17.2.2 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-31832 is a medium vulnerability (CVSS 5.4) in Umbraco Cms, published March 10, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 11th percentile. Fixed in Umbraco.Cms 16.5.1.
References
Left out here: 19 versions. The JSON record has them.