CVE-2026-31832 Umbraco Backoffice API Allows Unauthorized Modification of Domain Data
Authenticated users can modify domain data on unauthorized content nodes due to missing authorization checks in the Umbraco backoffice API.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-31832?
CVE-2026-31832 is a medium-severity missing authorization vulnerability in Umbraco Umbraco Cms, published on 10 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-639
Which versions are affected by CVE-2026-31832?
4 open source packages ship an affected version, including Umbraco.Cms. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
Umbraco.Cms NuGet | From 14.0.0 | 16.5.1 |
Umbraco.Cms NuGet | From 14.0.0 | 16.5.1 |
Umbraco.Cms NuGet | From 17.0.0 | 17.2.2 |
Umbraco.Cms NuGet | From 17.0.0 | 17.2.2 |
Products include Umbraco Umbraco Cms.
How do I fix CVE-2026-31832?
Upgrade Umbraco.Cms to a fixed version for your release line: 16.5.1 or 17.2.2.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-31832 being exploited?
There is no known exploitation of CVE-2026-31832 in the wild and no public exploit code.
Other vulnerabilities in Umbraco Umbraco Cms
- CVE-2025-67288 Umbraco CMS has an arbitrary file upload vulnerability
- CVE-2014-10074 File upload in n/a
- CVE-2012-1301 Server-side request forgery in n/a
- CVE-2012-10054 Umbraco CMS < 4.7.1 codeEditorSave.asmx RCE
- CVE-2025-32017 Umbraco has a Management API Vulnerability to Path Traversal With Authenticated Users
Sources
Also known as GHSA-fpvf-fvp5-996r.