CVE-2023-49279 Umbraco CMS vulnerable to stored XSS via SVG File Upload
An attacker with backoffice access can upload malicious SVG files to execute scripts in other users' browsers, potentially leading to account takeover.
- 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-2023-49279?
CVE-2023-49279 is a low-severity cross-site scripting vulnerability in Umbraco Umbraco Cms, published on 12 Dec 2023. 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 7.0.0 and prior to versions 7.15.11, 8.18.9, 10.7.0, 11.5.0, and 12.2.0, a user with access to the backoffice can upload SVG files that include scripts. If the user can trick another user to load the media directly in a browser, the scripts can be executed. Versions 7.15.11, 8.18.9, 10.7.0, 11.5.0, and 12.2.0 contain a patch for this issue. Some workarounds are available. Implement the server side file validation or serve all media from an different host (e.g cdn) than where Umbraco is hosted.
Weakness: CWE-79
Which versions are affected by CVE-2023-49279?
10 open source packages ship an affected version, including Umbraco.CMS. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
Umbraco.CMS NuGet | From 11.0.0 | 11.5.0 |
Umbraco.CMS NuGet | From 11.0.0 | 11.5.0 |
Umbraco.CMS NuGet | From 12.0.0 | 12.2.0 |
Umbraco.CMS NuGet | From 12.0.0 | 12.2.0 |
Umbraco.CMS NuGet | From 7.0.0 | 7.15.11 |
Umbraco.CMS NuGet | From 7.0.0 | 7.15.11 |
4 more packages
Umbraco.CMS NuGet | From 8.0.0 | 8.18.9 |
Umbraco.CMS NuGet | From 8.0.0 | 8.18.9 |
Umbraco.CMS NuGet | From 9.0.0 | 10.7.0 |
Umbraco.CMS NuGet | From 9.0.0 | 10.7.0 |
Products include Umbraco Umbraco Cms.
How do I fix CVE-2023-49279?
Upgrade Umbraco.CMS to a fixed version for your release line: 11.5.0, 12.2.0, 7.15.11 or 8.18.9.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2023-49279 being exploited?
There is no known exploitation of CVE-2023-49279 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-6xmx-85x3-4cv2.