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CVE-2020-5809
A stored XSS vulnerability exists in Umbraco CMS <= 8.9.1 or current. An authenticated user can inject arbitrary JavaScript code into…
Medium5.4EPSS 0.69%
- Published
- Updated
- Reserved
- Assigned by
- tenable
Description
A stored XSS vulnerability exists in Umbraco CMS <= 8.9.1 or current. An authenticated user can inject arbitrary JavaScript code into iframes when editing content using the TinyMCE rich-text editor, as TinyMCE is configured to allow iframes by default in Umbraco CMS.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Medium5.4 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.69% · top 47% of all CVEs (5 Nov 2026)
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The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.4.
Weakness
- Stored Cross-Site Scripting
- CWE-79 (opens in a new tab)All about CWE-79 and its CVEs
Affected products
Umbraco CMS
- affected <= 8.9.1 or current (unfixed)
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- NuGetUmbracoCms.CoreGHSA-95qr-67rx-9pgh (opens in a new tab)
References (1)
- https://www.tenable.com/security/research/tra-2020-59 (opens in a new tab)x_refsource_MISCx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-95qr-67rx-9pgh (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2020-5809)Record last updated .