High severity · published Nov 6, 2025
CVE-2025-12790
Rubygem-mqtt: rubygem-mqtt hostname validation
7.4
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RH
Red Hat Satellite 6 · Red Hat
All versions, or not specified · source: vendor
RU
ruby-mqtt · Nicholas J Humfrey
before 0.7.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-12790
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-12790
access.redhat.com
https://access.redhat.com/security/cve/CVE-2025-12790
bugzilla.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2413004
github.com
https://github.com/njh/ruby-mqtt/blob/main/NEWS.md#ruby-mqtt-version-070-2025-10-29