CVE-2026-111624
LOW
NVD
CVSS Score
3.7
Severity
LOW
Published
Oct 16, 2026
Vendor
unknown
Description
Umbraco CMS before 17.7.1 and 18.2.1 contains a missing authorization vulnerability that allows unauthenticated clients to connect to the backoffice PreviewHub and BackofficeHub SignalR hubs. Attackers can complete the SignalR negotiate step and receive refreshed notifications that disclose content keys, including unpublished content, and reveal editorial activity timing.
References
- https://github.com/umbraco/Umbraco-CMS/blob/release-18.2.0/src/Umbraco.Cms.Api.Management/Preview/PreviewHub.cs#L9-L11
- https://github.com/umbraco/Umbraco-CMS/blob/release-18.2.0/src/Umbraco.Cms.Api.Management/Preview/PreviewHubUpdater.cs#L58
- https://github.com/umbraco/Umbraco-CMS/commit/243e082479c777d0f585bbd2f8db571607767b22
- https://github.com/umbraco/Umbraco-CMS/commit/b4f6cfc9d0955f9d8443e68353db4a692e91bd94
- https://github.com/umbraco/Umbraco-CMS/releases/tag/release-17.7.1