Umbraco.Cms: XSS/HTML Injection in Umbraco Backoffice confirmation dialog
Impact
Authenticated users are able to inject HTML vulnerability into an input field, which is rendered in the confirmation dialog without proper output encoding.
Patches
This issue has been patched in 17.4.0
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| .NET (NuGet) | Umbraco.Cms | >= 14.0.0, < 17.4.0 | 17.4.0 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N- Weakness (CWE)
CWE-79- Platform
- .NET (NuGet)
- Package
Umbraco.Cms- Disclosed
- 21.05.2026
- Updated
- 11.10.2026 11:23
Sources and licenses
OSV / GitHub Advisory Database - GHSA-vr9v-27gg-qgx4 - CC BY 4.0
Vulnerability history: Umbraco.Cms
All published vulnerabilities of this package (.NET (NuGet)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 29
- First → latest
- 05.2022 09.2026
- Without a fix
- 1
- Exploited in attacks
- 0
Severity breakdown
- High 5
- Medium 17
- Low 7
Disclosures per year
- 2022: 2
- 2023: 8
- 2024: 5
- 2025: 8
- 2026: 6
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Umbraco.Cms: XSS/HTML Injection in Umbraco Backoffice confirmation dialog this entry
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