Rubygem-mqtt: rubygem-mqtt hostname validation
Priority LOW 35CWE-29Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00376 31st percentileScored 2026-11-07
Fix Partial ruby-mqtt (Nicholas J Humfrey): 0.7.0mqtt (RubyGems): 0.7.0Red Hat: 1 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Nicholas J Humfrey | ruby-mqtt | before 0.7.0 | 0.7.0 | Patch available | CNA |
| Red Hat | Red Hat Satellite 6 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Satellite 6 | — | — | No fix listed | CNA |
| — | mqtt (RubyGems) | before 0.7.0 | 0.7.0 | Patch available | GHSA-9c5q-w6gr-fxcq |
- ruby-mqtt VendorNicholas J Humfrey Affected before 0.7.0 Fixed in 0.7.0 Patch available CNA
- Red Hat Satellite 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Satellite 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
- mqtt (RubyGems) Vendor— Affected before 0.7.0 Fixed in 0.7.0 Patch available GHSA-9c5q-w6gr-fxcq
Remediation
- Fix · CNA ruby-mqtt (Nicholas J Humfrey) Fixed in 0.7.0
- Fix · GHSA-9c5q-w6gr-fxcq mqtt (RubyGems) Fixed in 0.7.0 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Low. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Satellite 6 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-02 Threatist record created from CVE-2025-12790
- 2026-10-03 Alias added: GHSA-9c5q-w6gr-fxcq
References
Sources
- CVE-2025-12790 · CVE Program
- CVE-2025-12790 · NVD
- FIRST EPSS
- GHSA-9c5q-w6gr-fxcq · GitHub Advisory Database · CC BY 4.0
- CVE-2025-12790 · Red Hat security data · CC BY 4.0
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