CVE-2025-48953 Umbraco Vulnerable to By-Pass of Configured Allowed Extensions for File Uploads
Attackers can bypass configured file extension restrictions in Umbraco CMS to upload malicious files, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2025-48953?
CVE-2025-48953 is a medium-severity vulnerability in Umbraco Umbraco Cms, published on 3 Jun 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Umbraco is an ASP.NET content management system (CMS). Starting in version 14.0.0 and prior to versions 15.4.2 and 16.0.0, it's possible to upload a file that doesn't adhere with the configured allowable file extensions via a manipulated API request. The issue is patched in versions 15.4.2 and 16.0.0. No known workarounds are available.
Weakness: CWE-434
Which versions are affected by CVE-2025-48953?
2 open source packages ship an affected version, including Umbraco.Cms. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
Umbraco.Cms NuGet | From 14.0.0 | 15.4.2 |
Umbraco.Cms NuGet | From 14.0.0 | 15.4.2 |
Products include Umbraco Umbraco Cms.
How do I fix CVE-2025-48953?
Upgrade Umbraco.Cms to 15.4.2 or later.
Is CVE-2025-48953 being exploited?
There is no known exploitation of CVE-2025-48953 in the wild and no public exploit code.
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-fr6r-p8hv-x3c4.