# CVE-2026-19243: HKUDS nanobot Shell Allowlist shell.py ExecTool._spawn os command injection


- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/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
- **Fix available:** No
- **Published:** 7 Aug 2026
- **Updated:** 11 Aug 2026
- **Also known as:** GHSA-m259-67hc-p7v5

## What is CVE-2026-19243?

CVE-2026-19243 is a medium-severity vulnerability in HKUDS nanobot, published on 7 Aug 2026. 

### Official description

A security vulnerability has been detected in HKUDS nanobot up to 0.2.1. Impacted is the function ExecTool._guard_command/ExecTool._spawn of the file nanobot/agent/tools/shell.py of the component Shell Allowlist Handler. Such manipulation leads to os command injection. The attack can be executed remotely. The exploit has been disclosed publicly and may be used. Upgrading to version 0.3.0 is recommended to address this issue. The name of the patch is 4562. It is advisable to upgrade the affected component. Multiple issues were reported to the project. They reacted with a high level of professionalism and kindness: "These five reports are variants of the same root cause: validation of shell commands containing multiple segments, wrappers, comments, or chained commands. The issue was fixed by validating every executable shell segment against the configured allowlist".

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-2026-19243?


## How do I fix CVE-2026-19243?

No fix has been published for CVE-2026-19243 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-19243 being exploited?

There is no known exploitation of CVE-2026-19243 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-19243 and fix it if it is affected.

What it is: CVE-2026-19243 is a medium-severity vulnerability in HKUDS nanobot, published on 7 Aug 2026. 
Exploitation: There is no known exploitation of CVE-2026-19243 in the wild and no public exploit code.

Affected product: HKUDS nanobot. 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-2026-19243/ (Markdown: https://insights.sbomify.com/CVE-2026-19243/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-19243
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-19243
- OSV: https://osv.dev/vulnerability/CVE-2026-19243

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-19243/
Summaries are generated and may contain mistakes; the official description above is the record.