CVE-2025-3899 Cross-site scripting in Modicon Controllers M241/M251
Authenticated attackers can inject scripts into the Modicon web server certificates page to read or modify victim browser data.
- 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-2025-3899?
CVE-2025-3899 is a medium-severity cross-site scripting vulnerability in Schneider Electric Modicon Controllers M241/M251, published on 10 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
CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability exists in Certificates page on Webserver that could cause an unvalidated data injected by authenticated malicious user leading to modify or read data in a victim’s browser.
Weakness: CWE-79
Which versions are affected by CVE-2025-3899?
How do I fix CVE-2025-3899?
No fix has been published for CVE-2025-3899 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-2025-3899 being exploited?
There is no known exploitation of CVE-2025-3899 in the wild and no public exploit code.
Sources
Also known as GHSA-j34m-g9vq-47p3.