Pageant is an SSH agent for Windows, commonly used with PuTTY. It keeps SSH keys available in memory and can perform authentication operations on their behalf, so users do not need to repeatedly enter a key passphrase. Applications can communicate with the agent to request authentication without directly handling the private key.
Because Pageant is a bridge between applications and sensitive credentials, its integration is a security boundary. A compromised or untrusted program may try to misuse agent access, while flaws in software that transfers keys to Pageant can expose data or create other risks. Defenses include limiting which programs can access the agent, protecting the computer while keys are loaded, and keeping both Pageant and applications that integrate with it updated.