# CVE-2018-20225: Supply chain in n/a

> Attackers can hijack private package installations via public indexes when using --extra-index-url, leading to arbitrary code execution.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 8 May 2020
- **Updated:** 15 Apr 2026
- **Also known as:** GHSA-7p5p-7qq5-cc86, MINI-4fr4-36h6-gcc5, ROOT-OS-DEBIAN-12-CVE-2018-20225, UBUNTU-CVE-2018-20225

## What is CVE-2018-20225?

CVE-2018-20225 is a high-severity vulnerability in n/a, published on 8 May 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

An issue was discovered in pip (all versions) because it installs the version with the highest version number, even if the user had intended to obtain a private package from a private index. This only affects use of the --extra-index-url option, and exploitation requires that the package does not already exist in the public index (and thus the attacker can put the package there with an arbitrary version number). NOTE: it has been reported that this is intended functionality and the user is responsible for using --extra-index-url securely

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2018-20225?

It affects 1 product.


Products: Pypa Pip.

## How do I fix CVE-2018-20225?

Change a configuration setting.

## Is CVE-2018-20225 being exploited?

There is no known exploitation of CVE-2018-20225 in the wild and no public exploit code.

Public exploit code:

- Demonstrating CVE-2018-20225 (github_poc): https://github.com/brabster/cve-2018-20225

## Other vulnerabilities in n/a

- [CVE-2013-1629](https://insights.sbomify.com/CVE-2013-1629/): Improper Input Validation in pip (medium 6.8)
- [CVE-2026-13346](https://insights.sbomify.com/CVE-2026-13346/): pip absolute path traversal during download from malicious package indexes (medium 5.6)
- [CVE-2023-5752](https://insights.sbomify.com/CVE-2023-5752/): Mercurial configuration injectable in repo revision when installing via pip (medium 5.5)
- [CVE-2026-8643](https://insights.sbomify.com/CVE-2026-8643/): pip can extract console_scripts and gui_scripts outside installation directory (medium 4.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-20225 and fix it if it is affected.

What it is: CVE-2018-20225 is a high-severity vulnerability in n/a, published on 8 May 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2018-20225 in the wild and no public exploit code.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2018-20225/ (Markdown: https://insights.sbomify.com/CVE-2018-20225/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-20225
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-20225
- OSV: https://osv.dev/vulnerability/CVE-2018-20225

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-20225/
Summaries are generated and may contain mistakes; the official description above is the record.