What’s Vulnerable › Vulnerabilities

CVE-2025-12790: Rubygem-mqtt: rubygem-mqtt hostname validation

• Severity: high (CVSS 7.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-11-06 · updated 2026-10-18
• Weakness: CWE-29

Description

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.

Affected products

• Nicholas J Humfrey ruby-mqtt: before 0.7.0 — fixed in 0.7.0
• Red Hat Satellite 6: all versions

How to fix

Upgrade to a fixed version: Nicholas J Humfrey ruby-mqtt 0.7.0. Check the vendor advisory for mitigations.

References

• https://access.redhat.com/security/cve/CVE-2025-12790
• https://bugzilla.redhat.com/show_bug.cgi?id=2413004
• https://github.com/njh/ruby-mqtt/blob/main/NEWS.md#ruby-mqtt-version-070-2025-10-29

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