# CVE-2026-79623: FishCodeTech Muteki Default Local Worker Backend settings.json os command injection

> Remote attackers can execute arbitrary OS commands via the Default Local Worker Backend settings in FishCodeTech Muteki.

- **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
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Aug 2026
- **Updated:** 27 Aug 2026
- **Also known as:** GHSA-w4x2-2pcx-2cpc

## What is CVE-2026-79623?

CVE-2026-79623 is a medium-severity command injection vulnerability in FishCodeTech Muteki, published on 25 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A security vulnerability has been detected in FishCodeTech Muteki up to 0.2.5. The affected element is an unknown function of the file .claude/settings.json of the component Default Local Worker Backend. The manipulation leads to os command injection. The attack can be initiated remotely. The exploit has been disclosed publicly and may be used. The issue was closed with the comment (translated from Chinese): "The project will be refactored and shut down."

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-2026-79623?


## How do I fix CVE-2026-79623?

No fix has been published for CVE-2026-79623 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-79623 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-79623 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-79623 and fix it if it is affected.

What it is: CVE-2026-79623 is a medium-severity command injection vulnerability in FishCodeTech Muteki, published on 25 Aug 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-2026-79623 exists.

Affected product: FishCodeTech Muteki. 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-2026-79623/ (Markdown: https://insights.sbomify.com/CVE-2026-79623/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-79623
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-79623
- OSV: https://osv.dev/vulnerability/CVE-2026-79623

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-79623/
Summaries are generated and may contain mistakes; the official description above is the record.