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Fencer Vulns
high 7.4

CVE-2025-12790 json

Rubygem-mqtt: rubygem-mqtt hostname validation

published 2025-11-06 12 mo ago modified 2026-10-18 21 d ago also GHSA-9c5q-w6gr-fxcq , EUVD-2025-38162

cvss
7.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 31%
public exploits
0
none known

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.

Patch / fix

  • rubygems mqtt 0.7.0
  • Nicholas J Humfrey ruby-mqtt 0.7.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-12790 updated cvss 7.4

rubygem-mqtt: rubygem-mqtt hostname validation

  • Red Hat Satellite 6 rubygem-mqtt
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
12 mo ago

Exploit prediction

0.38% chance of exploitation in the next 30 days, higher than 31% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
GitHub 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
rubygems mqtt
<0.7.0
0.7.0

Affected products

  • Nicholas J Humfrey ruby-mqtt
  • Red Hat Red Hat Satellite 6

Classification

Weakness
  • CWE-29 Path Traversal: '\..\filename'

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.