CVE-2020-5811 Authenticated path traversal in Umbraco CMS
Authenticated attackers can write arbitrary files outside expected directories during package installation in Umbraco CMS, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-5811?
CVE-2020-5811 is a medium-severity path traversal vulnerability in Umbraco Umbraco Cms, published on 30 Dec 2020. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
An authenticated path traversal vulnerability exists during package installation in Umbraco CMS <= 8.9.1 or current, which could result in arbitrary files being written outside of the site home and expected paths when installing an Umbraco package.
Weakness: CWE-22
Which versions are affected by CVE-2020-5811?
2 open source packages ship an affected version, including UmbracoCms. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
UmbracoCms NuGet | All versions | 8.9.2 |
UmbracoCms NuGet | All versions | 8.9.2 |
Products include Umbraco Umbraco Cms.
How do I fix CVE-2020-5811?
Upgrade UmbracoCms to 8.9.2 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2020-5811 being exploited?
There is no known exploitation of CVE-2020-5811 in the wild and no public exploit code.
Public exploit code: 1 Exploit-DB entry.
Other vulnerabilities in Umbraco Umbraco Cms
- CVE-2025-67288 Umbraco CMS has an arbitrary file upload vulnerability
- CVE-2014-10074 File upload in n/a
- CVE-2012-1301 Server-side request forgery in n/a
- CVE-2012-10054 Umbraco CMS < 4.7.1 codeEditorSave.asmx RCE
- CVE-2025-32017 Umbraco has a Management API Vulnerability to Path Traversal With Authenticated Users
Sources
Also known as GHSA-936x-wgqv-hhgq.