Affected: gitpython-developers GitPython

GitPython before 3.1.60 contains a regular expression denial of service vulnerability in Actor.name_email_regex that processes commit author and committer fields. Attackers can craft a commit object with a malformed author field containing an unterminated angle bracket to cause quadratic backtracking, exhausting CPU resources for over two minutes per commit access.

Affected: PyPI: GitPython

### Summary

GitPython's `Actor.name_email_regex` regular expression (`git/util.py`, line 863) is vulnerable to catastrophic backtracking (ReDoS — Regular Expression Denial of Service). When GitPython parses the `author` or `committer` header of a git commit object that contains a long string with an unterminated `<` (no matching `>`), the Python regex engine enters quadratic backtracking, causing complete single-threaded CPU exhaustion proportional to the square of the input length.

A single crafted commit object can block any GitPython API call that reads `.author` or `.committer` for **over two minutes per invocation**, enabling denial of service against CI runners, code-hosting backends, repository-scanning pipelines, or any service that processes commits from third-party or untrusted repositories.

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### Details

**Vulnerable file and line:**

`git/util.py`, line 863:

```python name_email_regex = re.compile(r"(.*) <(.*?)>") ```

This regex is evaluated inside `Actor._from_string()` (line 909) every time GitPython resolves a commit's `.author` or `.committer` property.

**Full call chain — from public API to vulnerable sink:**

commit.author # any ordinary GitPython API call └── git/objects/commit.py:917 Commit._deserialize() └── git/objects/util.py:341 parse_actor_and_date(author_line) └── git/util.py:909 Actor._from_string(string) └── Actor.name_email_regex.search(string) ← VULNERABLE

`author_line` is decoded directly from the raw bytes of the git commit ob…

Affected: PyPI: gitpython

GitPython before 3.1.60 contains a regular expression denial of service vulnerability in Actor.name_email_regex that processes commit author and committer fields. Attackers can craft a commit object with a malformed author field containing an unterminated angle bracket to cause quadratic backtracking, exhausting CPU resources for over two minutes per commit access.