# CVE-2018-7166: Information disclosure in Node.js

> An argument processing flaw in Node.js Buffer.alloc() allows attackers to read uninitialized memory, potentially exposing sensitive information.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Aug 2018
- **Updated:** 8 Oct 2026
- **Also known as:** GHSA-6v28-c2x2-8p46, RHBA-2019:0772

## What is CVE-2018-7166?

CVE-2018-7166 is a high-severity vulnerability in Nodejs Node.js, published on 21 Aug 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In all versions of Node.js 10 prior to 10.9.0, an argument processing flaw can cause `Buffer.alloc()` to return uninitialized memory. This method is intended to be safe and only return initialized, or cleared, memory. The third argument specifying `encoding` can be passed as a number, this is misinterpreted by `Buffer's` internal "fill" method as the `start` to a fill operation. This flaw may be abused where `Buffer.alloc()` arguments are derived from user input to return uncleared memory blocks that may contain sensitive information.

Weakness: CWE-908 (Use of Uninitialized Resource), CWE-226 (Sensitive Information in Resource Not Removed Before Reuse)

## Which versions are affected by CVE-2018-7166?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `rh-nodejs10-nodejs` | Red Hat:rhel_software_collections:3::el7 | All versions | 0:10.10.0-3.el7 |
| `rh-nodejs10-nodejs-debuginfo` | Red Hat:rhel_software_collections:3::el7 | All versions | 0:10.10.0-3.el7 |
| `rh-nodejs10-nodejs-devel` | Red Hat:rhel_software_collections:3::el7 | All versions | 0:10.10.0-3.el7 |
| `rh-nodejs10-nodejs-docs` | Red Hat:rhel_software_collections:3::el7 | All versions | 0:10.10.0-3.el7 |
| `rh-nodejs10-npm` | Red Hat:rhel_software_collections:3::el7 | All versions | 0:6.4.1-10.10.0.3.el7 |

Products: Nodejs Node.js.

## How do I fix CVE-2018-7166?

Upgrade to a fixed version.

## Is CVE-2018-7166 being exploited?

There is no known exploitation of CVE-2018-7166 in the wild and no public exploit code.

## Other vulnerabilities in Nodejs Node.js

- [CVE-2023-32002](https://insights.sbomify.com/CVE-2023-32002/): Security feature bypass in Node (critical 9.8)
- [CVE-2016-6303](https://insights.sbomify.com/CVE-2016-6303/): Integer overflow in n/a (critical 9.8)
- [CVE-2017-15896](https://insights.sbomify.com/CVE-2017-15896/): Security feature bypass in Node.js (critical 9.1)
- [CVE-2018-7160](https://insights.sbomify.com/CVE-2018-7160/): Server-side request forgery in Node.js (high 8.8)
- [CVE-2018-12120](https://insights.sbomify.com/CVE-2018-12120/): Misconfiguration in Node.js (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-7166 and fix it if it is affected.

What it is: CVE-2018-7166 is a high-severity vulnerability in Nodejs Node.js, published on 21 Aug 2018. 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-2018-7166 in the wild and no public exploit code.

Affected product: Nodejs Node.js. 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-2018-7166/ (Markdown: https://insights.sbomify.com/CVE-2018-7166/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-7166
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-7166
- OSV: https://osv.dev/vulnerability/CVE-2018-7166

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-7166/
Summaries are generated and may contain mistakes; the official description above is the record.