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Vulnerability · Published Mar 10, 2026 · Assigned by GitHub_M

CVE-2026-31832Umbraco Backoffice API Allows Unauthorized Modification of Domain Data

Medium 5.4

In plain English

A medium-severity authorization bypass via user-controlled key in Umbraco-CMS from umbraco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.4Medium
Exploit odds (30 days)0.2%top 89.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
NuGetumbraco.cms16.5.1GHSA-fpvf-fvp5-996r
NuGetumbraco.cms17.2.2GHSA-fpvf-fvp5-996r

Affected products (as reported)

VendorProductVersions
umbraco Umbraco-CMS >= 14.0.0, < 16.5.1>= 17.0.0, < 17.2.0

Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

References