CVE-2026-111624 Umbraco CMS before 17.7.1 and 18.2.1 Missing Authorization on SignalR Hubs
Unauthenticated attackers can access SignalR hubs to disclose unpublished content keys and editorial activity timing in Umbraco CMS.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-111624?
CVE-2026-111624 is a medium-severity missing authorization vulnerability in Umbraco-CMS, published on 16 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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can complete the SignalR negotiate step and receive refreshed notifications that disclose content keys, including unpublished content, and reveal editorial activity timing.
Weakness: CWE-306
Which versions are affected by CVE-2026-111624?
How do I fix CVE-2026-111624?
No fix has been published for CVE-2026-111624 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-111624 being exploited?
There is no known exploitation of CVE-2026-111624 in the wild and no public exploit code.
Sources
Also known as GHSA-4c5q-6c64-96j7, GHSA-q9r6-5jwm-rmgp.