CVE-2025-3902: Block Class - Moderately critical - Cross Site Scripting - SA-CONTRIB-2025-043

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-04-23 · updated 2026-06-17
Weakness: CWE-79

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.

Affected products

Drupal Block Class: from 4.0.0 before 4.0.1 — fixed in 4.0.1

How to fix

Upgrade to a fixed version: Drupal Block Class 4.0.1. Check the vendor advisory for mitigations.

References

https://www.drupal.org/sa-contrib-2025-043

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