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CVE CVE-2026-31833

CVE-2026-31833

ASP.NET

Severity: MEDIUM
CVSS: 6.7CVSS
Published: 2026-03-10
Last modified: 2026-03-18
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L
CWE: CWE-79

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.

References

https://github.com/umbraco/Umbraco-CMS/security/advisories/GHSA-vrqc-59mw-qqg7

Summary

Description

References