CVE-2025-12790: MQTT does not validate hostnames

November 6, 2025

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.

References

access.redhat.com/security/cve/CVE-2025-12790
bugzilla.redhat.com/show_bug.cgi?id=2413004
github.com/advisories/GHSA-9c5q-w6gr-fxcq
github.com/njh/ruby-mqtt/blob/main/NEWS.md
nvd.nist.gov/vuln/detail/CVE-2025-12790

Code Behaviors & Features

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