CVE-2026-67323: GitPython RCE Vulnerability

CVE-2026-67323 Overview

CVE-2026-67323 is a command injection vulnerability in GitPython versions before 3.1.51. The library fails to guard against dangerous Git options passed as keyword arguments in Repo.archive() and git.ls_remote(). Attackers can inject options such as --exec or --upload-pack to achieve arbitrary command execution. A related flaw allows Repo.iter_commits() and Repo.blame() to accept revision arguments beginning with a dash, letting a value like --output=<path> cause Git to open and truncate an arbitrary file. Exploitation requires an application that forwards attacker-controlled arguments to these methods.

Critical Impact
Arbitrary command execution and arbitrary file truncation in applications embedding GitPython when attacker-controlled input reaches vulnerable methods.

Affected Products

GitPython versions before 3.1.51
Python applications embedding GitPython that pass user input to Repo.archive() or git.ls_remote()
Python applications embedding GitPython that pass user input to Repo.iter_commits() or Repo.blame()

Discovery Timeline

2026-08-01 - CVE-2026-67323 published to NVD
2026-08-05 - Last updated in NVD database

Technical Details for CVE-2026-67323

Vulnerability Analysis

GitPython is a Python library that wraps the git command-line binary. The vulnerability stems from missing sanitization of keyword arguments in Repo.archive() and git.ls_remote(). These methods translate keyword arguments directly into Git command-line options. When an application forwards untrusted input as a keyword, an attacker can supply Git options that execute arbitrary programs.

The --exec option for git archive and the --upload-pack option for ls-remote both instruct Git to invoke an external command. Passing a value such as upload-pack=/tmp/malicious.sh causes Git to execute the referenced binary during the remote operation.

A secondary defect affects Repo.iter_commits() and Repo.blame(). These methods do not reject revision strings that begin with a leading dash. An argument such as --output=/etc/passwd is interpreted by Git as an output redirection flag, causing Git to open and truncate the specified file. This vulnerability is categorized under CWE-77 (Improper Neutralization of Special Elements used in a Command).

Root Cause

GitPython constructs Git invocations by mapping Python keyword arguments to CLI flags without an allowlist and without enforcing the -- separator before positional revision arguments. Git treats leading-dash tokens as options regardless of position, so any unfiltered value can be reinterpreted as a flag.

Attack Vector

An attacker submits a crafted string to an application endpoint that forwards the value to a vulnerable GitPython method. For command execution, the payload supplies a Git option that references an attacker-controlled binary reachable on the host. For file truncation, the payload supplies a revision beginning with a dash that Git parses as an output-writing option.

The vulnerability requires an application-level sink. GitPython itself does not expose a network service. See the GitHub Security Advisory GHSA-956x-8gvw-wg5v and the VulnCheck Advisory on GitPython for reference details.

Detection Methods for CVE-2026-67323

Indicators of Compromise

Process telemetry showing git archive or git ls-remote invocations that include --exec= or --upload-pack= values pointing to writable or user-controlled paths.
Git child processes spawning unexpected binaries such as shells, interpreters, or scripts from /tmp, /var/tmp, or application upload directories.
Unexpected truncation or zero-byte modification of files owned by the account running the Python application.
Application logs recording revision or remote parameters beginning with --.

Detection Strategies

Perform software composition analysis (SCA) across Python environments to identify GitPython installations below 3.1.51.
Instrument application code paths that call Repo.archive(), git.ls_remote(), Repo.iter_commits(), and Repo.blame() to log argument values.
Deploy endpoint process monitoring to flag git child processes whose command lines contain --exec or --upload-pack outside of expected automation.
Correlate web request parameters with subsequent git process launches to spot user input reaching Git flags.

Monitoring Recommendations

Enable command-line auditing (auditdexecve, Sysmon Event ID 1) and alert on git executions containing --exec, --upload-pack, or --output=.
Baseline the set of binaries invoked by the application service account and alert on deviations.
Monitor file integrity on sensitive paths that the application user can reach to catch truncation attempts.

How to Mitigate CVE-2026-67323

Immediate Actions Required

Upgrade GitPython to version 3.1.51 or later across all Python environments, containers, and CI/CD runners.
Audit application source code for calls to Repo.archive(), git.ls_remote(), Repo.iter_commits(), and Repo.blame() that receive untrusted input.
Reject any revision, remote, or option value that begins with a dash before passing it to GitPython.
Restrict the service account running the application to the minimum filesystem permissions required.

Patch Information

GitPython 3.1.51 guards the affected methods against dangerous options and rejects leading-dash revision arguments. Refer to the GitHub Security Advisory GHSA-956x-8gvw-wg5v for patch commits and release notes.

Workarounds

Validate all user-supplied strings against a strict allowlist before invoking GitPython methods.
Enforce the -- separator manually when constructing revision lists, and strip any argument beginning with -.
Run the application under a dedicated low-privilege user with no write access to sensitive system paths.
Isolate Git operations inside a sandbox or container with noexec mounts on writable directories.

bash

# Configuration example
pip install --upgrade 'GitPython>=3.1.51'
pip show GitPython | grep -i version