An issue in AsyncSSH before 2.14.1 allows attackers to control the extension info message (RFC 8308) via a man-in-the-middle attack, aka a "Rogue Extension Negotiation."
https://www.terrapin-attack.com
https://security.netapp.com/advisory/ntap-20231222-0001/
https://github.com/ronf/asyncssh/security/advisories/GHSA-cfc2-wr2v-gxm5
https://github.com/ronf/asyncssh/blob/develop/docs/changes.rst
https://github.com/advisories/GHSA-cfc2-wr2v-gxm5
http://packetstormsecurity.com/files/176280/Terrapin-SSH-Connection-Weakening.html