Vulnerable releases include many 12.2, 12.3, 12.4 trains. Fixed releases are typically 12.4(24)T5 or higher, 12.2(33)SXI5, 15.1(1)T1, etc. Check for exact fixed versions.
Example fixed banner after upgrade:
SSH-2.0-Cisco-2.22 (IOS 15.9) SSH-2.0-Cisco-2.36 (IOS-XE 16.x)
: Refers to a specific legacy version of the Cisco SSH stack found in various Cisco IOS, IOS XE, and older PIX/ASA software releases.