Details
**Affected:** `GitPython` **3.1.61** (latest release) and `main` — `git/objects/submodule/base.py`. `git diff 3.1.61 origin/main -- git/objects/submodule/` is empty, so both are identical here.
---
## The gap
The fix for `GHSA-hmq2-w58f-27jc` added `Submodule._validated_name()` and wired it into `update()` and five siblings, closing the `.gitmodules` **name** → `.git/modules/<name>` traversal. The other attacker-controlled `.gitmodules` field, **`path`**, is read raw:
```python
# git/objects/submodule/base.py:172-177
def _set_cache_(self, attr):
if attr in ("path", "_url", "_branch_path"):
reader = self.config_reader()
self.path = reader.get("path") # raw .gitmodules value
```
and GitPython's own containment guard is applied in only two of the places that consume it:
```
400: def _to_relative_path(cls, parent_repo, path) # the guard (abspath + commonpath containment)
542: path = cls._to_relative_path(repo, path) # add() — guarded
1041: module_checkout_path = self._to_relative_path(self.repo, module_path) # move() — guarded
```
`update()` validates only the name and then uses the path-derived absolute location directly:
```
788: self._validated_name(self.name) # NAME only
801: checkout_module_abspath = self.abspath # derived from self.path — unguarded
821: os.makedirs(checkout_module_abspath, exist_ok=True)
```
So `path = ../../../tmp/escaped` in an attacker-authored `.gitmodules` selects the directory that gets created and, on the clone path, populated from the submodule URL. The same absolute location is what `force_remove` hands to `shutil.rmtree`.
The asymmetry is the argument: this is not a missing concept — the project wrote `_to_relative_path()` precisely for this, and `add()`/`move()` use it. `update()` does not.
## Honest limits (please read before rating)
- **The most common flow is not affected.** `Repo.clone_from(...)` → `repo.submodules` → `sm.update(init=True)` re-derives `path` from a canonical tree lookup, and real git refuses to check out a tree containing a `..` component, so an evil `.gitmodules` never lands in the working tree in the first place. A reachable trigger therefore requires the victim's code to name a **non-HEAD commit** (a historical-commit API such as `submodule_update(previous_commit=...)`).
- **The researcher did not build that end-to-end trigger.** The researcher only verified first-hand the code above: the guard's two call sites, the name-only validation in `update()`, and the unguarded `abspath` → `os.makedirs()` flow at 3.1.61 == `main`.
## Suggested fix
Apply the guard the project already has, wherever the path is consumed:
```python
# in update(), before deriving abspath (and in any other consumer of self.path):
checkout_rel = self._to_relative_path(self.repo, self.path) # raises if it escapes the working tree
```
Better still, validate at the boundary: reject a `.gitmodules` entry whose `path` is absolute or contains a `..` component when the section is first read in `_set_cache_()`/`iter_items()`, so no consumer can be added later without the check. A regression test with `path = ../escaped` alongside the existing `name` test would pin both fields.
## Prior art checked
`GHSA-hmq2-w58f-27jc` (this is a residual of its fix, in the sibling field, not a re-report) plus the repository's 30 published advisories — none mentions the `path` field or `_to_relative_path`. Searched issues and PRs for `_to_relative_path`, `gitmodules path` and `submodule traversal`: no report of this.
## Credit
**kta1kri**.
---
## Appendix — `EVIDENCE_gitpython_path_unguarded_20260901.txt` (inlined; advisories accept no attachments)
```text
=== EVIDENCE: GitPython — the .gitmodules 'path' field reaches os.makedirs()/clone unguarded ===
Mon Aug 31 18:45:22 UTC 2026
--- artifact: tag 3.1.61 (latest release); git diff 3.1.61 origin/main -- git/objects/submodule/ is empty ---
--- the containment guard GitPython owns, and its only two call sites ---
33: _to_relative_path,
400: def _to_relative_path(cls, parent_repo: "Repo", path: PathLike) -> PathLike:
407: path = _to_relative_path(parent_repo.working_tree_dir, path)
542: path = cls._to_relative_path(repo, path)
1041: module_checkout_path = self._to_relative_path(self.repo, module_path)
--- the parent fix (_validated_name) call sites: it validates the NAME ---
309: def _validated_name(cls, name: str) -> str:
321: name = cls._validated_name(name)
541: cls._validated_name(name)
788: self._validated_name(self.name)
1040: self._validated_name(self.name)
1181: self._validated_name(self.name)
1439: self._validated_name(self.name)
1440: self._validated_name(new_name)
1489: self._validated_name(self.name)
--- update(): name validated, path not; abspath -> os.makedirs ---
try:
self._validated_name(self.name)
# ENSURE REPO IS PRESENT AND UP-TO-DATE
# END early abort if init is not allowed
checkout_module_abspath = self.abspath
module_abspath = self._module_abspath(self.repo, self.path, self.name)
# ``git submodule deinit`` leaves the repository in
# ``.git/modules`` and empties the checkout. Reconnect that retained
# repository instead of trying to clone over it.
if not dry_run and osp.isdir(module_abspath):
try:
git.Repo(module_abspath)
except InvalidGitRepositoryError:
pass
else:
if osp.lexists(checkout_module_abspath) and (
osp.islink(checkout_module_abspath)
or not osp.isdir(checkout_module_abspath)
or os.listdir(checkout_module_abspath)
):
raise OSError(
"Module directory at %r does already exist and is non-empty" % checkout_module_abspath
)
os.makedirs(checkout_module_abspath, exist_ok=True)
self._write_git_file_and_module_config(checkout_module_abspath, module_abspath)
mrepo = git.Repo(checkout_module_abspath)
--- where self.path comes from (raw .gitmodules value) ---
def _set_cache_(self, attr: str) -> None:
if attr in ("path", "_url", "_branch_path"):
reader: SectionConstraint = self.config_reader()
# Default submodule values.
try:
self.path = reader.get("path")
except cp.NoSectionError as e:
```
