CVE-2026-114145

### Summary `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. ### Details The checkout path is validated too late, after the clone has already mutated disk. This breaks the "validate before mutation" invariant that commit 43a43cd8 ("Validate submodule checkout and metadata paths before mutation") set out to enforce. Submodule.add() calls the permissive path check before cloning, and the strict check only reaches the ".git" alias at index time, after _clone_repo has written to disk: git/objects/submodule/base.py (Submodule.add) 599: path = cls._to_relative_path(repo, path) # accepts ".git/hooks" 673: mrepo = cls._clone_repo(repo, url, path, name, ...) # clones into <worktree>/.git/hooks 714: index.add([sm], write=True) # strict check only triggers here git/index/base.py (IndexFile._preprocess_add_items) 732: _validate_repo_path(entry.path) # rejects ".git", too late _to_relative_path only blocks `..`/absolute/out-of-tree paths; `.git` aliases are rejected only by _validate_repo_path, which was added in 3.2.0 (commit a75aedf3) and runs at the index boundary. The ValueError it raises at line 732 does not roll back what _clone_repo already wrote. Version-dependent behavior: - 3.2.0 .. tip bda18e08: _validate_repo_path raises ValueError at index.add, but the hook is already on disk and is not removed (incorrect