# CVE-2020-7774: Prototype Pollution

> Prototype pollution in the y18n library allows attackers to modify object prototypes, potentially leading to code execution or privilege escalation.

- **Severity:** High 7.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Nov 2020
- **Updated:** 16 Sep 2024
- **Also known as:** ALPINE-CVE-2020-7774, CLEANSTART-2026-SV85138, CLEANSTART-2026-UW35844, CLSA-2026-1782867615, DEBIAN-CVE-2020-7774, GHSA-c4w7-xm78-47vh, ROOT-APP-NPM-CVE-2020-7774, UBUNTU-CVE-2020-7774

## What is CVE-2020-7774?

CVE-2020-7774 is a high-severity vulnerability in Oracle Graalvm, published on 17 Nov 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The package y18n before 3.2.2, 4.0.1 and 5.0.5, is vulnerable to Prototype Pollution.

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

## Which versions are affected by CVE-2020-7774?

6 open source packages ship an affected version, including y18n. It affects 3 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `y18n` | npm | All versions | 3.2.2 |
| `y18n` | npm | All versions | 3.2.2 |
| `y18n` | npm | From 4.0.0 | 4.0.1 |
| `y18n` | npm | From 4.0.0 | 4.0.1 |
| `y18n` | npm | From 5.0.0 | 5.0.5 |
| `y18n` | npm | From 5.0.0 | 5.0.5 |

Products: Oracle Graalvm, Siemens Sinec Infrastructure Network Services, Y18n Project Y18n.

## How do I fix CVE-2020-7774?

Upgrade y18n to a fixed version for your release line: 3.2.2, 4.0.1 or 5.0.5.

## Is CVE-2020-7774 being exploited?

There is no known exploitation of CVE-2020-7774 in the wild and no public exploit code.

## Other vulnerabilities in Oracle Graalvm

- [CVE-2025-50059](https://insights.sbomify.com/CVE-2025-50059/): Security feature bypass in Oracle GraalVM Enterprise Edition (high 8.6)
- [CVE-2021-32803](https://insights.sbomify.com/CVE-2021-32803/): Arbitrary File Creation/Overwrite via insufficient symlink protection due to directory cache poisoning (high 8.2)
- [CVE-2021-32804](https://insights.sbomify.com/CVE-2021-32804/): Arbitrary File Creation/Overwrite due to insufficient absolute path sanitization (high 8.2)
- [CVE-2025-30749](https://insights.sbomify.com/CVE-2025-30749/): Code injection in Oracle GraalVM Enterprise Edition (high 8.1)
- [CVE-2025-50106](https://insights.sbomify.com/CVE-2025-50106/): Code injection in Oracle GraalVM Enterprise Edition (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-7774 and fix it if it is affected.

What it is: CVE-2020-7774 is a high-severity vulnerability in Oracle Graalvm, published on 17 Nov 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-2020-7774 in the wild and no public exploit code.

Affected packages and fixed versions:
- y18n (npm): affected all versions; fixed in 3.2.2
- y18n (npm): affected all versions; fixed in 3.2.2
- y18n (npm): affected from 4.0.0; fixed in 4.0.1
- y18n (npm): affected from 4.0.0; fixed in 4.0.1
- y18n (npm): affected from 5.0.0; fixed in 5.0.5
- y18n (npm): affected from 5.0.0; fixed in 5.0.5

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-2020-7774/ (Markdown: https://insights.sbomify.com/CVE-2020-7774/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-7774
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-7774
- OSV: https://osv.dev/vulnerability/CVE-2020-7774

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-7774/
Summaries are generated and may contain mistakes; the official description above is the record.