THE article from Rapid7 discusses the security vulnerability CVE-2026-66066 affecting Ruby on Rails applications that use Active Storage with the Vips image processor, enabling arbitrary file reads. It highlights that versions below 7.2.3.2, between 8.0 and 8.0.5.1, and between 8.1 and 8.1.3.1 are affected. The vulnerability arises when an attacker can upload files with manipulated content types leading to the potential for remote code execution (RCE).
The article provides a detailed analysis of how an attacker can exploit this weakness, reproducing the attack chain across different Rails versions, and notes how recent patches work by blocking unsafe operations in the Vips library. Furthermore, the article discusses the steps for remediation, emphasizing the importance of keeping dependencies updated.