# CVE-2026-89066: OS command injection in the task synthesis component in projen

> Attackers can execute arbitrary commands on developer workstations or CI runners via shell metacharacters in projen project configurations.

- **Severity:** High 8.4 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 11 Sep 2026
- **Updated:** 11 Sep 2026
- **Also known as:** GHSA-q6g4-h6vc-vqm8

## What is CVE-2026-89066?

CVE-2026-89066 is a high-severity command injection vulnerability in AWS projen, published on 11 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Improper neutralization of special elements used in an OS command in the task synthesis component in projen before 0.103.0 might allow context-dependent attackers to execute arbitrary commands on a developer workstation or continuous integration runner via shell metacharacters in project configuration values and repository file names that are interpolated into generated task definitions.

To remediate this issue, users should upgrade to version 0.103.0 and then re-synthesize the project so that .projen/tasks.json is regenerated with the corrected task definitions. Upgrading alone is not sufficient because the generated task definition file is committed to the repository.

Weakness: CWE-88 (Improper Neutralization of Argument Delimiters in a Command), CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2026-89066?


## How do I fix CVE-2026-89066?

No fix has been published for CVE-2026-89066 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-89066 being exploited?

There is no known exploitation of CVE-2026-89066 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-89066 and fix it if it is affected.

What it is: CVE-2026-89066 is a high-severity command injection vulnerability in AWS projen, published on 11 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-89066 in the wild and no public exploit code.

Affected product: AWS projen. 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-2026-89066/ (Markdown: https://insights.sbomify.com/CVE-2026-89066/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-89066
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-89066
- OSV: https://osv.dev/vulnerability/CVE-2026-89066

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-89066/
Summaries are generated and may contain mistakes; the official description above is the record.