CVE-2026-40126 DOM-based Cross-Site Scripting in OutSystems Service Center
A low-privileged attacker can execute arbitrary JavaScript in the victim's browser by uploading a file with a malicious filename in OutSystems Service Center.
- 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-2026-40126?
CVE-2026-40126 is a medium-severity cross-site scripting vulnerability in OutSystems Service Center, published on 17 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
OutSystems Service Center is vulnerable to a DOM-based Cross-Site Scripting (XSS) attack that can be exploited by a low-privileged attacker via the upload of a file with a malicious filename containing JavaScript code. The vulnerability exists in all locations where a file can be attached and prepared for upload to the server.
This issue was fixed in OutSystems Service Center version 11.41.2
Weakness: CWE-79
Which versions are affected by CVE-2026-40126?
How do I fix CVE-2026-40126?
No fix has been published for CVE-2026-40126 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-2026-40126 being exploited?
There is no known exploitation of CVE-2026-40126 in the wild and no public exploit code.
Sources
Also known as GHSA-wpg4-f3mj-hxh3.