CVE-2019-9898

Potential recycling of random numbers used in cryptography exists within PuTTY before 0.71.

CVE-2019-9894

A remotely triggerable memory overwrite in RSA key exchange in PuTTY before 0.71 can occur before host key verification.

CVE-2019-9897

Multiple denial-of-service attacks that can be triggered by writing to the terminal exist in PuTTY versions before 0.71.