# CVE-2026-100865: Heym before 0.0.53 Remote Code Execution via eval() Sandbox Escape

> Authenticated users can execute arbitrary code via malicious workflow conditions due to insufficient sandboxing in Heym.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 27 Sep 2026
- **Updated:** 28 Sep 2026
- **Also known as:** GHSA-grmf-qq9c-vgpp

## What is CVE-2026-100865?

CVE-2026-100865 is a high-severity code injection vulnerability in heymrun heym, published on 27 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Heym before 0.0.53 evaluates workflow condition expressions using Python's eval() with insufficient sandboxing in the workflow executor service. Authenticated users can edit workflow condition nodes or import malicious templates to execute arbitrary Python and OS commands as the backend process user.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-100865?


## How do I fix CVE-2026-100865?

No fix has been published for CVE-2026-100865 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-100865 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100865 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-100865 and fix it if it is affected.

What it is: CVE-2026-100865 is a high-severity code injection vulnerability in heymrun heym, published on 27 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100865 exists.

Affected product: heymrun heym. 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-2026-100865/ (Markdown: https://insights.sbomify.com/CVE-2026-100865/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-100865
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-100865
- OSV: https://osv.dev/vulnerability/CVE-2026-100865

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-100865/
Summaries are generated and may contain mistakes; the official description above is the record.