Affected: gitpython-developers GitPython

GitPython before 3.1.59 fails to disable merge_includes when parsing .gitmodules, allowing attackers to disclose local file content by including arbitrary file paths via [include] directives. Attackers can craft a malicious .gitmodules file with include directives pointing to sensitive files; when repo.submodules is accessed, GitConfigParser raises MissingSectionHeaderError embedding the target file's first line verbatim in the exception message.

Affected: PyPI: GitPython

# [HIGH] Arbitrary local file content disclosure via `[include]` directive in untrusted `.gitmodules` (`SubmoduleConfigParser` never disables `merge_includes`)

- **CWE:** CWE-200 (Exposure of Sensitive Information) / CWE-73 (External Control of File Name or Path) - **Affected component:** `git/objects/submodule/base.py`, `Submodule._config_parser()` (~line 273) constructing `SubmoduleConfigParser(fp_module, read_only=read_only)`; `git/config.py`, `GitConfigParser.__init__` (`merge_includes` default), `GitConfigParser.read()`/`_included_paths()` (include-path resolution, ~lines 630-685), `GitConfigParser._read()` (~line 493-498, `MissingSectionHeaderError`) - **Affected version:** GitPython at HEAD (`9729ed3b948f2bde09f1f188c5311e172212b67e`, 2026-08-05, VERSION `3.1.58`)

## Reachability `GitConfigParser.__init__` defaults `merge_includes=True`: any config file it parses has its `[include]` (and, when a `repo=` is supplied, `[includeIf ...]`) directives followed and merged in. The maintainers already recognized this as dangerous for one specific case and fixed it in commit `41ecc6a4` ("Disable merge_includes in config writers"), which passes `merge_includes=False` when `Repo.config_writer()` builds its parser (`git/repo/base.py`).

That fix never touched `Submodule._config_parser()`. This method builds the parser used for **every** read of a repo's submodule configuration — `repo.submodules`, `Submodule.iter_items()`, `Submodule.config()` — via `SubmoduleConfigParser(fp_mod…

Affected: PyPI: gitpython

GitPython before 3.1.59 fails to disable merge_includes when parsing .gitmodules, allowing attackers to disclose local file content by including arbitrary file paths via [include] directives. Attackers can craft a malicious .gitmodules file with include directives pointing to sensitive files; when repo.submodules is accessed, GitConfigParser raises MissingSectionHeaderError embedding the target file's first line verbatim in the exception message.