# CVE-2020-7746: Prototype Pollution

> Prototype pollution in Chart.js allows attackers to manipulate object prototypes, potentially leading to code execution or security bypasses.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:U/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 29 Oct 2020
- **Updated:** 16 Sep 2024
- **Also known as:** DEBIAN-CVE-2020-7746, GHSA-h68q-55jf-x68w, UBUNTU-CVE-2020-7746

## What is CVE-2020-7746?

CVE-2020-7746 is a high-severity vulnerability in chart.js, published on 29 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

This affects the package chart.js before 2.9.4. The options parameter is not properly sanitized when it is processed. When the options are processed, the existing options (or the defaults options) are deeply merged with provided options. However, during this operation, the keys of the object being set are not checked, leading to a prototype pollution.

Weakness: CWE-1321 (Improperly Controlled Modification of Object Prototype Attributes)

## Which versions are affected by CVE-2020-7746?

2 open source packages ship an affected version, including chart.js. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `chart.js` | npm | All versions | 2.9.4 |
| `chart.js` | npm | All versions | 2.9.4 |

Products: Chartjs Chart.js.

## How do I fix CVE-2020-7746?

Upgrade chart.js to 2.9.4 or later.

## Is CVE-2020-7746 being exploited?

There is no known exploitation of CVE-2020-7746 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-7746 and fix it if it is affected.

What it is: CVE-2020-7746 is a high-severity vulnerability in chart.js, published on 29 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-7746 in the wild and no public exploit code.

Affected packages and fixed versions:
- chart.js (npm): affected all versions; fixed in 2.9.4
- chart.js (npm): affected all versions; fixed in 2.9.4

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-2020-7746/ (Markdown: https://insights.sbomify.com/CVE-2020-7746/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-7746
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-7746
- OSV: https://osv.dev/vulnerability/CVE-2020-7746

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-7746/
Summaries are generated and may contain mistakes; the official description above is the record.