CVE-2026-111624
lowUmbraco CMS before 17.7.1 and 18.2.1 contains a missing authorization vulnerability that allows unauthenticated clients to connect to the backoffice PreviewHub…
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can complete the SignalR negotiate step and receive refreshed notifications that disclose content keys, including unpublished content, and reveal editorial activity timing.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/umbraco/Umbraco-CMS/blob/release-18.2.0/src/Umbraco.Cms.Api.Management/... disclosure@vulncheck.com
- https://github.com/umbraco/Umbraco-CMS/blob/release-18.2.0/src/Umbraco.Cms.Api.Management/... disclosure@vulncheck.com
- https://github.com/umbraco/Umbraco-CMS/commit/243e082479c777d0f585bbd2f8db571607767b22 disclosure@vulncheck.com
- https://github.com/umbraco/Umbraco-CMS/commit/b4f6cfc9d0955f9d8443e68353db4a692e91bd94 disclosure@vulncheck.com
- https://github.com/umbraco/Umbraco-CMS/releases/tag/release-17.7.1 disclosure@vulncheck.com
- https://github.com/umbraco/Umbraco-CMS/releases/tag/release-18.2.1 disclosure@vulncheck.com
- https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-4c5q-6c64-96j7 disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/umbraco-cms-before-17.7.1-and-18.2.1-missing-authoriz... disclosure@vulncheck.com