CVE-2018-17256 Umbraco CMS vulnerable to stored XSS
Authenticated users can inject arbitrary web script via the Header Name field in Umbraco CMS, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2018-17256?
CVE-2018-17256 is a medium-severity cross-site scripting vulnerability in Umbraco Umbraco Cms, published on 27 Nov 2018. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
Persistent cross-site scripting (XSS) vulnerability in Umbraco CMS 7.12.3 allows authenticated users to inject arbitrary web script via the Header Name of a content (Blog, Content Page, etc.). The vulnerability is exploited when updating or removing public access of a content.
Weakness: CWE-79
Which versions are affected by CVE-2018-17256?
2 open source packages ship an affected version, including umbraco. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
umbraco NuGet | All versions to 7.12.3 | None |
umbraco NuGet | All versions to 7.12.3 | None |
Products include Umbraco Umbraco Cms.
How do I fix CVE-2018-17256?
No fix has been published for CVE-2018-17256 yet. Limit exposure of the affected software until one is available.
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-2018-17256 being exploited?
There is no known exploitation of CVE-2018-17256 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-wrrj-r2j4-969w.