EUVD-2026-81902Published

Umbraco is an ASP.NET CMS. Prior to 13.15.1, 17.5.3, and 18.0.2, the Content Delivery API applies member and Public Access checks to the directly requested node but not to referenced nodes serialized through Content Picker or Multi-Node Tre…

Historical advisory saved 28 Oct 2026 08:46:16 UTC. The publisher may have updated it since then. Latest advisory.

euvd · EUVD-2026-81902

Published

Umbraco is an ASP.NET CMS. Prior to 13.15.1, 17.5.3, and 18.0.2, the Content Delivery API applies member and Public Access checks to the directly requested node but not to referenced nodes serialized through Content Picker or Multi-Node Tree Picker properties, including pickers nested in Block List, Block Grid, or Rich Text Editor blocks. When DeliveryApi:PublicAccess is enabled, an anonymous caller can retrieve a protected node's name, route, and id through an unprotected referencing node and use ?expand to retrieve full property values. When the Delivery API is instead gated by the organization-wide API key, a key holder can still bypass per-node Public Access through the same expansion path. The same RequestContextOutputExpansionStrategyV2 and ElementOnlyOutputExpansionStrategy path also bypasses allowed or disallowed content-type alias restrictions for referenced content. Direct requests for the protected node still return 401, and no integrity or availability impact is established. This issue is fixed in versions 13.15.1, 17.5.3, and 18.0.2.

Additional publisher context

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: Sep 17, 2026, 3:44:24 PM

dateUpdated: Sep 17, 2026, 5:23:18 PM

Source published: Sep 17, 2026, 3:44:24 PM (timezone not stated)
Source modified: Sep 17, 2026, 5:23:18 PM (timezone not stated)
Saved here: 28 Oct 2026 08:46:16 UTC
Source terms: ENISA EUVD · source terms and attribution apply

Original source record · Cite this exact observation · Complete original publisher JSON

Source: euvd · ENISA EUVD · source terms and attribution apply. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.

EUVD CVSS 4.0 · 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N