CVE-2026-114145: GitPython validates a submodule's ".git" path only after cloning into it (RCE)

create_submodule(name, path, url) clones a submodule into the repo’s own .git directory before it rejects the path. A path of “.git/hooks” is accepted by the pre-clone check, so the submodule is cloned straight into the live hooks directory, and a file named post-checkout in the submodule becomes an executable .git/hooks/post-checkout. On 3.2.0+ the later index check does raise ValueError, but only after the clone already wrote to disk, and it does not remove the planted hook; on 3.1.x there is no such check and the call succeeds silently. Either way the hook runs on the next git operation (e.g. checkout), giving code execution.