CVE-2026-18478 Stored XSS in Magnolia CMS
An attacker with editor privileges can inject arbitrary HTML and JavaScript into image names, leading to stored XSS execution when images are viewed.
- 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
- None listed
What is CVE-2026-18478?
CVE-2026-18478 is a medium-severity cross-site scripting vulnerability in Magnolia CMS, published on 10 Aug 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Magnolia CMS is vulnerable to Stored XSS in import functionality. An attacker with editor privileges can inject arbitrary HTML and JS into the name of uploaded image, which will be rendered/executed when opening uploaded image.
The issue was fixed in version 6.3.10
Weakness: CWE-79
Which versions are affected by CVE-2026-18478?
How do I fix CVE-2026-18478?
No fix has been published for CVE-2026-18478 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-2026-18478 being exploited?
There is no known exploitation of CVE-2026-18478 in the wild and no public exploit code.
Sources
Also known as GHSA-jp3f-93v6-xm3f.