If you see SSH-2.0-Cisco-1.25 , the device be vulnerable, but you must verify the IOS version.

Classified with a CVSS v3.1 score of 10.0 , indicating maximum severity.

Cisco’s Product Security Incident Response Team (PSIRT) noted attempted exploitation of this vulnerability in the wild as of June 2025. Exposure and Attack Surface

The presence of ssh-2.0-cisco-1.25 is rarely a false positive for trouble. It correlates with several major security weaknesses:

Vulnerabilities are assigned a by MITRE. No CVE uses the string ssh-2.0-cisco-1.25 . Security tools that flag this banner as a “critical vulnerability” are using outdated or heuristic signatures. The banner only indicates:

Below is a practical guide to understanding, detecting, and mitigating the risk.

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