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can complete the SignalR negotiate step and receive refreshed notifications that disclose content keys, including unpublished content, and reveal editorial activity timing.
Published: 2026-10-16
Score: 6.3 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Fri, 16 Oct 2026 17:45:00 +0000

Type Values Removed Values Added
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can complete the SignalR negotiate step and receive refreshed notifications that disclose content keys, including unpublished content, and reveal editorial activity timing.
Title Umbraco CMS before 17.7.1 and 18.2.1 Missing Authorization on SignalR Hubs
First Time appeared Umbraco
Umbraco umbraco Cms
Weaknesses CWE-306
CPEs cpe:2.3:a:umbraco:umbraco_cms:*:*:*:*:*:*:*:*
Vendors & Products Umbraco
Umbraco umbraco Cms
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}


Subscriptions

Umbraco Umbraco Cms
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-16T17:39:00.093Z

Reserved: 2026-10-16T14:31:11.287Z

Link: CVE-2026-111624

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-16T18:17:42.280

Modified: 2026-10-16T18:17:42.280

Link: CVE-2026-111624

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses