What’s Vulnerable › Vulnerabilities

CVE-2025-61939: Columbia Weather Systems MicroServer Improper Restriction of Communication Channel to Intended Endpoints

• Severity: medium (CVSS 4.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-01-07 · updated 2026-10-07
• Weakness: CWE-923

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.

Affected products

• Columbia Weather Systems MicroServer: before MS_4.1_14142 — fixed in MS_4.1_14142

How to fix

Upgrade to a fixed version: Columbia Weather Systems MicroServer MS_4.1_14142. Check the vendor advisory for mitigations.

References

• https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2026/icsa-26-006-01.json
• https://www.cisa.gov/news-events/ics-advisories/icsa-26-006-01

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