Medium severity · published Jan 7, 2026
CVE-2025-61939
Columbia Weather Systems MicroServer Improper Restriction of Communication Channel to Intended Endpoints
4.4
CVSS
0.3%
EPSS
No
On KEV
Description
An unused function in MicroServer can start a reverse SSH connection to a vendor registered domain, without mutual authentication. An attacker on the local network with admin access to the web server, and the ability to manipulate DNS responses, can redirect the SSH connection to an attacker controlled device.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N
Attack vector
Local
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 19% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MI
MicroServer · Columbia Weather Systems
before MS_4.1_14142 · source: vendor
WM
Weather Microserver Firmware · Columbiaweather
before MS_4.1_14142 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-61939
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-61939
Third Party Advisory
https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-006-01.json
Third Party Advisory
https://www.cisa.gov/news-events/ics-advisories/icsa-26-006-01
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