CVE-2025-12790
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2025-12790- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-29
- Updated
- 2026-11-02
EUVDEUVD-2025-38162
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.
- Record
EUVD-2025-38162- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-9c5q-w6gr-fxcq
MQTT does not validate hostnames
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.
- Record
GHSA-9c5q-w6gr-fxcq- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-29
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-12790- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-29
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2025-12790- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-29
- Updated
- 2026-11-02
OSVGHSA-9c5q-w6gr-fxcq
MQTT does not validate hostnames
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.
- Record
GHSA-9c5q-w6gr-fxcq- CVSS 3.1
- 7.4 High
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-29
- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-12790 is a high vulnerability (CVSS 7.4) in Nicholas J Humfrey Ruby-mqtt, published November 6, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.38%, the 31st percentile. Fixed in mqtt 0.7.0.
References
access.redhat.com/security/cve/CVE-2025-12790
bugzilla.redhat.com/show_bug.cgi?id=2413004
github.com/njh/ruby-mqtt/blob/main/NEWS.md
nvd.nist.gov/vuln/detail/CVE-2025-12790