CVE-2026-31833
Last modified
CVE-2026-31833 is a medium-severity vulnerability rated 6.7/10 on the CVSS scale. Umbraco is an ASP.NET CMS. From 16.2.0 to before 16.5.1 and 17.2.2, An authenticated backoffice user with access to Settings can inject malicious HTML into property type descriptions. EPSS estimates a 0.26% chance of exploitation in the next 30 days.
Description
Umbraco is an ASP.NET CMS. From 16.2.0 to before 16.5.1 and 17.2.2, An authenticated backoffice user with access to Settings can inject malicious HTML into property type descriptions. Due to an overly permissive attributeNameCheck configuration (/.+/) in the UFM DOMPurify instance, event handler attributes such as onclick and onload, when used within Umbraco web components (umb-*, uui-*, ufm-*) were not filtered. This vulnerability is fixed in 16.5.1 and 17.2.2.
Metrics
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Umbraco | Umbraco Cms | >= 16.2.0, < 16.5.1 |
| Umbraco | Umbraco Cms | >= 17.0.0, < 17.2.2 |
References
Timeline
- Published
- Last Modified
- Status
- Analyzed
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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