{"id":"CVE-2026-111624","title":"Umbraco CMS before 17.7.1 and 18.2.1 Missing Authorization on SignalR Hubs","summary":"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 …","severity":"low","cvss":3.7,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","cvssSource":"cna","cwe":["CWE-306"],"vendor":"umbraco","product":"Umbraco-CMS","affected":["Umbraco-CMS >= 17.0.0 < 17.7.1","Umbraco-CMS >= 18.0.0 < 18.2.1"],"published":"2026-10-16","updated":"2026-10-16","sourceUpdated":"2026-10-16T17:39:00.093Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-111624","references":[{"url":"https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-4c5q-6c64-96j7","label":"GitHub Security Advisory (GHSA-4c5q-6c64-96j7)"},{"url":"https://github.com/umbraco/Umbraco-CMS/blob/release-18.2.0/src/Umbraco.Cms.Api.Management/Preview/PreviewHub.cs#L9-L11"},{"url":"https://github.com/umbraco/Umbraco-CMS/blob/release-18.2.0/src/Umbraco.Cms.Api.Management/Preview/PreviewHubUpdater.cs#L58"},{"url":"https://github.com/umbraco/Umbraco-CMS/commit/b4f6cfc9d0955f9d8443e68353db4a692e91bd94"},{"url":"https://github.com/umbraco/Umbraco-CMS/commit/243e082479c777d0f585bbd2f8db571607767b22"},{"url":"https://github.com/umbraco/Umbraco-CMS/releases/tag/release-18.2.1","label":"Umbraco-CMS release-18.2.1 Release Notes"},{"url":"https://github.com/umbraco/Umbraco-CMS/releases/tag/release-17.7.1","label":"Umbraco-CMS release-17.7.1 Release Notes"},{"url":"https://www.vulncheck.com/advisories/umbraco-cms-before-17.7.1-and-18.2.1-missing-authorization-on-signalr-hubs","label":"VulnCheck Advisory: Umbraco CMS before 17.7.1 and 18.2.1 Missing Authorization on SignalR Hubs"}],"tags":["cve.org"],"ingestedAt":"2026-10-16T18:43:08.690Z","slug":"CVE-2026-111624","body":"## Overview\n\nUmbraco 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can complete the SignalR negotiate step and receive refreshed notifications that disclose content keys, including unpublished content, and reveal editorial activity timing.\n\n## Affected\n\n- `Umbraco-CMS >= 17.0.0 < 17.7.1`\n- `Umbraco-CMS >= 18.0.0 < 18.2.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":20,"depthScoreParts":{"impact":20.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}