Rubygem MQTT Hostname Validation Missing Allows MITM
CVE-2025-12790 Published on November 6, 2025

Rubygem-mqtt: rubygem-mqtt hostname validation
A flaw was found in Rubygem MQTT. By default, the package used to not have hostname validation, resulting in possible Man-in-the-Middle (MITM) attack.

NVD

Vulnerability Analysis

CVE-2025-12790 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
NONE

Timeline

Reported to Red Hat.

Made public.

Weakness Type

Path Traversal: '\..\filename'

The software uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize '\..\filename' (leading backslash dot dot) sequences that can resolve to a location that is outside of that directory.


Products Associated with CVE-2025-12790

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Affected Versions

Nicholas J Humfrey ruby-mqtt: Red Hat Satellite 6: Red Hat Satellite 6:

Exploit Probability

EPSS
0.07%
Percentile
19.94%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.