# CVE-2026-16129: princezuda SafestClaw Built-in Web shell.py ShellAction._validate_command incomplete blacklist

> Incomplete blacklist in SafestClaw's shell validation allows local attackers to execute arbitrary commands via the built-in web interface.

- **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:** 18 Jul 2026
- **Updated:** 22 Jul 2026
- **Also known as:** GHSA-4ch8-fgcq-7558

## What is CVE-2026-16129?

CVE-2026-16129 is a medium-severity command injection vulnerability in princezuda SafestClaw, published on 18 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability has been found in princezuda SafestClaw up to 4.2.4. This vulnerability affects the function ShellAction._validate_command of the file src/safestclaw/actions/shell.py of the component Built-in Web Interface. Such manipulation leads to incomplete blacklist. An attack has to be approached locally. The exploit has been disclosed to the public and may be used. The presence of this vulnerability remains uncertain at this time. The project maintainer explains: "On paper you're correct, this is a vulnerability. In practice, nothing your AI generated shows how it makes users vulnerable. It's open source. Someone can mod the shell allow list or remove that system. Present an actual poc that shows a threat to users."

Weakness: CWE-184 (Incomplete List of Disallowed Inputs), CWE-183 (Permissive List of Allowed Inputs)

## Which versions are affected by CVE-2026-16129?


## How do I fix CVE-2026-16129?

No fix has been published for CVE-2026-16129 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-16129 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-16129 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-16129 and fix it if it is affected.

What it is: CVE-2026-16129 is a medium-severity command injection vulnerability in princezuda SafestClaw, published on 18 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-2026-16129 exists.

Affected product: princezuda SafestClaw. 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-2026-16129/ (Markdown: https://insights.sbomify.com/CVE-2026-16129/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-16129
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-16129
- OSV: https://osv.dev/vulnerability/CVE-2026-16129

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-16129/
Summaries are generated and may contain mistakes; the official description above is the record.