# CVE-2019-11839: Memory corruption in n/a

> Heap-based buffer overflow in njs Array.prototype.push allows attackers to execute arbitrary code or cause denial of service.

- **Severity:** Critical 9.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 May 2019
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-585q-jwfj-chw8

## What is CVE-2019-11839?

CVE-2019-11839 is a critical memory corruption vulnerability in n/a, published on 9 May 2019. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

njs through 0.3.1, used in NGINX, has a heap-based buffer overflow in Array.prototype.push after a resize, related to njs_array_prototype_push in njs/njs_array.c, because of njs_array_expand size mishandling.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2019-11839?

It affects 1 product.


Products: F5 Njs.

## How do I fix CVE-2019-11839?

No fix has been published for CVE-2019-11839 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-11839 being exploited?

There is no known exploitation of CVE-2019-11839 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2020-19692](https://insights.sbomify.com/CVE-2020-19692/): Memory corruption in n/a (critical 9.8)
- [CVE-2020-19695](https://insights.sbomify.com/CVE-2020-19695/): Memory corruption in n/a (critical 9.8)
- [CVE-2022-43286](https://insights.sbomify.com/CVE-2022-43286/): Use after free in n/a (critical 9.8)
- [CVE-2022-29379](https://insights.sbomify.com/CVE-2022-29379/): Denial of service in n/a (critical 9.8)
- [CVE-2022-27007](https://insights.sbomify.com/CVE-2022-27007/): Use after free in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-11839 and fix it if it is affected.

What it is: CVE-2019-11839 is a critical memory corruption vulnerability in n/a, published on 9 May 2019. 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-2019-11839 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-2019-11839/ (Markdown: https://insights.sbomify.com/CVE-2019-11839/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-11839
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-11839
- OSV: https://osv.dev/vulnerability/CVE-2019-11839

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-11839/
Summaries are generated and may contain mistakes; the official description above is the record.