In ssh in OpenSSH before 9.6, OS command injection might occur if a user name or host name has shell metacharacters, and this name is referenced by an expansion token in certain situations. For example, an untrusted Git repository can have a submodule with shell metacharacters in a user name or host name.
https://securelist.com/exploits-and-vulnerabilities-q3-2024/114839/
https://www.openwall.com/lists/oss-security/2023/12/18/2
https://www.openssh.com/txt/release-9.6
https://www.debian.org/security/2023/dsa-5586
https://support.apple.com/kb/HT214084
https://security.netapp.com/advisory/ntap-20240105-0005/
https://security.gentoo.org/glsa/202312-17
https://lists.debian.org/debian-lts-announce/2023/12/msg00017.html
https://github.com/openssh/openssh-portable/commit/7ef3787c84b6b524501211b11a26c742f829af1a