CVE-2025-3902 Block Class - Moderately critical - Cross Site Scripting - SA-CONTRIB-2025-043
Attackers can inject malicious scripts via the Block Class module, potentially compromising user sessions or site integrity.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2025-3902?
CVE-2025-3902 is a medium-severity cross-site scripting vulnerability in Drupal Block Class, published on 23 Apr 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Drupal Block Class allows Cross-Site Scripting (XSS).This issue affects Block Class: from 4.0.0 before 4.0.1.
Weakness: CWE-79
Which versions are affected by CVE-2025-3902?
It affects 1 product.
Linux distribution packages (1)
drupal/block_class Packagist:https://packages.drupal.org/8 | From 4.0.0 | 4.0.1 |
Products include Four Kitchens Block Class.
How do I fix CVE-2025-3902?
Upgrade to a fixed version.
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-2025-3902 being exploited?
There is no known exploitation of CVE-2025-3902 in the wild and no public exploit code.
Sources
Also known as DRUPAL-CONTRIB-2025-043, GHSA-v484-6wmj-xwfq.