# CVE-2026-16763: localstack serverless-localstack Configuration index.js os command injection

> Local attackers can execute arbitrary OS commands via the custom.localstack.docker.compose_file configuration argument in the serverless-localstack plugin.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 23 Jul 2026
- **Updated:** 24 Jul 2026
- **Also known as:** GHSA-64cc-4fc3-52m3

## What is CVE-2026-16763?

CVE-2026-16763 is a medium-severity command injection vulnerability in serverless-localstack, published on 23 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was identified in localstack serverless-localstack up to 1.4.0. The affected element is an unknown function of the file src/index.js of the component Configuration Handler. The manipulation of the argument custom.localstack.docker.compose_file leads to os command injection. An attack has to be approached locally. The exploit is publicly available and might be used. The project was informed of the problem early through an issue report but has not responded yet.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command), CWE-77 (Improper Neutralization of Special Elements used in a Command)

## Which versions are affected by CVE-2026-16763?


## How do I fix CVE-2026-16763?

No fix has been published for CVE-2026-16763 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-16763 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-16763 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-16763 and fix it if it is affected.

What it is: CVE-2026-16763 is a medium-severity command injection vulnerability in serverless-localstack, published on 23 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-16763 exists.

Affected product: serverless-localstack. 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-2026-16763/ (Markdown: https://insights.sbomify.com/CVE-2026-16763/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-16763
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-16763
- OSV: https://osv.dev/vulnerability/CVE-2026-16763

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-16763/
Summaries are generated and may contain mistakes; the official description above is the record.