CVE-2025-12790: 
Ruby vulnerability analysis and mitigation

A security vulnerability (CVE-2025-12790) was discovered in Rubygem MQTT, identified on November 6, 2025. The vulnerability stems from the package's default configuration lacking hostname validation, which affects the MQTT Ruby gem package. This flaw was initially reported by Red Hat and has been classified with a high severity rating (NVD, Red Hat Security).

The vulnerability has been assigned a CVSS v3.1 base score of 7.4 (HIGH) with the vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N. The technical assessment indicates that the vulnerability is network-accessible (AV:N) but requires high attack complexity (AC:H). No privileges (PR:N) or user interaction (UI:N) are required for exploitation. The scope is unchanged (S:U), with potential high impacts on both confidentiality and integrity (C:H, I:H), while availability is not affected (A:N) (NVD).

The vulnerability's primary impact lies in its potential to enable Man-in-the-Middle (MITM) attacks due to the absence of hostname validation in the default configuration. This could allow attackers to intercept and potentially manipulate communication between MQTT clients and servers, compromising the confidentiality and integrity of transmitted data (Red Hat Security).

The vulnerability affects Red Hat Satellite 6 systems. Users are advised to update their systems with the latest security patches when they become available. The issue has been addressed in the development branch, with fixes planned for release (Red Hat Bugzilla).