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SkillTotal

Is CodeNib MCP server safe?

Some risk - review before installing
Notable — review in context (a capability is not a malicious indicator):
  • Possible command injection (shell + dynamic command)
  • Unsafe deserialization
  • Python shell/command execution

What to do: Read the findings below before installing: each one opens the exact line of code it was found on.

CodeNib MCP server is an MCP server analyzed by SkillTotal's deterministic static scanner. The scan found no malicious indicators, though 2 risky constructs are reported for review. It can: dynamic code execution, filesystem read, filesystem write, mcp tools detected, network egress and shell execution — capabilities are what the code can do, not a verdict on intent. Risk score 40/100 (medium).

codenib 0.2.4

python_package · pypi:codenib
MEDIUM
40
/ 100 risk score
Snapshot · scanned Oct 17, 2026 · codenib@0.2.4 · engine 0.76.0 / ruleset 78

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Automated static-analysis result. It can contain false positives and false negatives, and is not a claim about the intent of CodeNib MCP server's authors. Report a false positive.

Capabilities — what this component can do (not a risk score):
dynamic code executionfilesystem readfilesystem writemcp tools detectednetwork egressshell execution

Behavioral traits

How this component maps to the CSA agentic threat model. Descriptive — it never affects the risk score.

Tool surface
Tool Usage
Execution authority
Tool Access Control / Direct Tool Access
Filesystem reach
Tool Execution Context
Network egress
Interaction & Communication / Direct Communication
Unsafe deserialization
General Protections / Input Validation

Findings (9)

HIGHPossible command injection (shell + dynamic command)ST-CMDI-PY

The code builds an OS command out of values that can change at runtime, then runs it through a shell.

proc = subprocess.Popen(  # noqa: S602 — loose shell policy by design
            command,
            shell=True,
            cwd=cwd,
            stdin=subprocess.DEVNULL,
            stdout=subprocess.PIPE,
            stderr=subprocess. …

Why it matters: If any of those values come from untrusted input, an attacker can run their own commands on the machine.

Fix: Pass arguments as a list without shell=True (e.g. subprocess.run(['git', 'checkout', branch])); never build a shell string from external input. If a shell is unavoidable, quote with shlex.quote.

HIGHUnsafe deserializationST-DESERIALIZE-PY

It loads data with a format that can rebuild arbitrary objects (e.g. pickle, or unsafe YAML).

Why it matters: Feeding such a loader untrusted data can execute code hidden inside that data.

Fix: Deserialize untrusted data with a safe format/loader: JSON, or yaml.safe_load / Loader=SafeLoader. Reserve pickle/marshal for data you fully control.

CapabilityPython dynamic code executionnot scored · severity highST-DYN-PY

The code turns strings into live code at runtime (eval / new Function / exec).

self._model = self._model.to(device).eval()
_load_lm(
                model_name,
                dtype=dtype or torch.bfloat16,
                model_class=model_class,
                attn_implementation="eager",
            )
            .to(device)
            .eval()
_load_lm(
                model_name,
                dtype=dtype or torch.bfloat16,
                model_class=model_class,
            )
            .to(device)
            .eval()

Why it matters: If those strings aren't fixed and trusted, they become a way to run arbitrary code.

Fix: Avoid evaluating dynamically constructed code; if unavoidable, ensure the input is a trusted constant and never derived from external data.

CapabilityPython shell/command executionnot scored · severity highST-SHELL-PY

The component can run operating-system commands or spawn processes.

process = subprocess.Popen(command, cwd=root, stdout=output, stderr=error)
proc = subprocess.Popen(  # noqa: S603 - fixed interpreter and module
                command,
                stdin=subprocess.PIPE,
                stdout=stdout_file,
                stderr=stderr_file,
                start_new_session= …
proc = subprocess.Popen(  # noqa: S603 - fixed executable and argv
            command,
            cwd=cwd,
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
            bufsize=0,
            start_new_session=True, …
proc = subprocess.Popen(  # noqa: S602 — loose shell policy by design
            command,
            shell=True,
            cwd=cwd,
            stdin=subprocess.DEVNULL,
            stdout=subprocess.PIPE,
            stderr=subprocess. …
result = subprocess.run(
            ["git", "-C", str(repo_path), "config", "--get", "remote.origin.url"],
            check=True,
            capture_output=True,
            text=True,
            timeout=10,
        )
result = subprocess.run(command, check=False, capture_output=True)
result = subprocess.run(
            [
                "git",
                "-c",
                f"safe.directory={repo}",
                "-C",
                str(repo),
                "rev-parse",
                "HEAD", …
process = await asyncio.create_subprocess_exec(
                *request.argv,
                cwd=str(request.cwd),
                env=environment,
                stdin=(
                    asyncio.subprocess.PIPE
                    if …
return subprocess.run(
            ("git", "rev-parse", "HEAD"),
            cwd=workspace,
            capture_output=True,
            text=True,
            check=True,
            timeout=15,
            env={
                "GIT_CONFI …
return subprocess.run(
        ("git", "status", "--porcelain=v1", "-z", "--untracked-files=all"),
        cwd=request.workspace,
        capture_output=True,
        check=True,
        timeout=30,
    ).stdout
result = subprocess.run(
            ("git", *args),
            cwd=cwd,
            capture_output=True,
            text=True,
            check=True,
            timeout=60,
            env={
                "GIT_CONFIG_NOSYSTEM": "1", …
return subprocess.run(
            ["git", "rev-parse", "HEAD"],
            cwd=repo_path,
            capture_output=True,
            text=True,
            check=True,
        ).stdout.strip()
return subprocess.run(
        ("git", *args),
        cwd=workspace,
        capture_output=True,
        text=True,
        check=False,
        timeout=30,
        env=_GIT_ENV,
    )
result = subprocess.run(
        ["git", "-C", str(repo_path), "rev-parse", "HEAD"],
        capture_output=True,
        check=False,
        text=True,
    )
result = subprocess.run(
            ["git", "-C", repo_path, *args],
            capture_output=True,
            text=True,
            timeout=15,
        )
result_git = subprocess.run(
                ["git", "rev-parse", "HEAD"],
                cwd=repo_path,
                capture_output=True,
                text=True,
                check=True,
            )
resolved = subprocess.run(
        ["git", "-C", repo_path, "rev-parse", "--verify", revision],
        check=False,
        capture_output=True,
        env=_zoekt_git_env(),
    )
result = subprocess.run(
        [
            "git",
            "-C",
            repo_path,
            "ls-tree",
            "-rz",
            "--full-tree",
            source_commit,
        ],
        check=False,
result = subprocess.run(
        ["git", "-C", repo_path, "ls-files", "--stage", "-z"],
        check=False,
        capture_output=True,
        env=_zoekt_git_env(),
    )
result = subprocess.run(
        ["git", "-C", repo_path, "ls-files", "--others", "-z"],
        check=False,
        capture_output=True,
        env=_zoekt_git_env(),
    )
process = subprocess.Popen(
            ["git", "-C", repo_path, "cat-file", "--batch"],
            stdin=subprocess.PIPE,
            stdout=subprocess.PIPE,
            stderr=subprocess.DEVNULL,
            bufsize=0,
            env=_z …
subprocess.run(
                            cmd,
                            check=True,
                            capture_output=True,
                            text=True,
                            env=_zoekt_git_env(), …
result = subprocess.run(
                ["git", "rev-parse", "HEAD"],
                cwd=repo_path,
                capture_output=True,
                text=True,
                timeout=5,
            )
subprocess.run(
            [
                "git",
                "-c",
                f"safe.directory={Path(source_repo).expanduser().resolve()}",
                "-C",
                str(source_repo),
                "worktree", …
return subprocess.run(
            ["git", "-c", f"safe.directory={resolved}", "-C", str(repo), *args],
            check=True,
            stdout=subprocess.PIPE,
            stderr=subprocess.PIPE,
            text=True,
        ).stdout. …

Why it matters: Powerful and often legitimate — confirm the commands aren't built from untrusted input.

Fix: Confirm the command and its arguments are fully controlled and not derived from untrusted input; avoid shell=True.

CapabilityPython filesystem readnot scored · severity mediumST-FS-PY-READ

The component reads files from disk.

return self.authenticated_snapshot(
            relative,
            max_bytes=max_bytes,
        ).read_bytes()
with open("/proc/self/mountinfo", encoding="utf-8") as mountinfo:
return binding.read_bytes(max_bytes=max_bytes)
return binding.read_bytes(max_bytes=max_bytes)
return path.read_text(encoding="utf-8", errors="replace").splitlines()[line]
source_line = source.read_text(
                encoding="utf-8", errors="strict"
            ).splitlines()[int(line)]
(self.repo_root / path)
                    .read_text(encoding="utf-8", errors="replace")
raw = source.read_bytes(record.path, max_bytes=10 * 1024 * 1024)
with open(config_file) as f:
skill_doc = skill_md_file.read_text(encoding="utf-8")
with open(file_path, "rb") as fh:
text = file_path.read_text(encoding="utf-8", errors="replace")
with open(file_path, "rb") as fh:
or candidate_metadata.read_bytes() != expected_metadata_bytes
or candidate.read_bytes(
                    CONTEXT_ARTIFACT_MANIFEST,
                    max_bytes=expected_metadata_size,
                )
else reader.read_bytes(path, max_bytes=max_bytes)
payload = reader.read_bytes(
            path,
            max_bytes=MAX_PORTABLE_DOCUMENTS_JSON_BYTES,
        )
reader.read_bytes(relative, max_bytes=max_bytes),
payload = reader.read_bytes(relative, max_bytes=_MAX_CONFIG_JSON_BYTES)
payload = reader.read_bytes(relative, max_bytes=_MAX_CONFIG_JSON_BYTES)
lines = resolved.read_text(encoding="utf-8", errors="replace").splitlines()
digest = hashlib.sha256(resolved.read_bytes()).hexdigest()
json.loads(manifest.read_text(encoding="utf-8"))
return __import__("hashlib").sha256(target.read_bytes()).hexdigest()

Why it matters: Usually legitimate, but worth confirming it can't be steered into reading sensitive files.

Fix: Confirm which files are read and that paths cannot be influenced by untrusted input to reach sensitive locations.

CapabilityPython filesystem write/deletenot scored · severity mediumST-FS-PY-WRITE

The component writes or deletes files on disk.

os.unlink(relative.name, dir_fd=parent)
target.write_bytes(text.encode("utf-8"))
target.write_bytes(_json_bytes(value))
shutil.copytree(source, destination)
shutil.copy2(source, target)
os.unlink(name, dir_fd=directory_descriptor)
path.write_bytes(_json_bytes(normalized))
config_path.write_bytes(_json_bytes(config))
output.write_bytes(_json_bytes(payload))
config_path.write_bytes(_json_bytes(config))
metadata_path.write_bytes(_json_bytes(metadata))
temporary.write_text(
        json.dumps(value, indent=2, sort_keys=True) + "\n", encoding="utf-8"
    )
temporary.write_text(value, encoding="utf-8")
_write_text(prefix.with_suffix(".txt"), attempt.response)
_write_text(root / "final-report.md", render_markdown(result))
temporary.write_text(
            json.dumps(serialized, indent=2, sort_keys=True) + "\n", encoding="utf-8"
        )
with open(output_path, "w", encoding="utf-8") as f:
with open(output_path, "w", encoding="utf-8") as f:
temporary.write_text(json.dumps(report, indent=2) + "\n", encoding="utf-8")
with open(meta_path, "w") as f:
path.write_text(json.dumps(body, indent=2) + "\n", encoding="utf-8")
with open(self.cache_path, "w", encoding="utf-8") as fh:
with open(cache_path, "w", encoding="utf-8") as f:

Why it matters: Usually legitimate, but worth confirming the paths can't be controlled by untrusted input.

Fix: Confirm which files are written/deleted and that paths cannot be influenced by untrusted input.

CapabilityNode.js network egressnot scored · severity mediumST-NET-NODE

The component makes outbound network requests.

import{i as s,s as l,a as m}from"./index-CGflccWM.js";const c=m();async function f(n,e){let t="";try{const r=(await n.text()).trim();if(r)try{const i=JSON.parse(r);t=typeof i.detail=="string"?i.detail:r}catch{t=r}}catch{}const o=t.replace(/ …

Why it matters: Usually legitimate, but confirm the destinations are expected and no sensitive data leaves.

Fix: Confirm the destination hosts are expected and that no sensitive data is sent off-host.

CapabilityPython network egressnot scored · severity mediumST-NET-PY

The component makes outbound network requests.

with requests.post(
            "https://openrouter.ai/api/v1/chat/completions",
            headers={"Authorization": f"Bearer {key}", "X-OpenRouter-Title": "CodeNib"},
            json={
                "model": config.planner_model, …
parsed = urllib.parse.urlsplit(value.rstrip("/"))
return urllib.parse.urlunsplit(parsed)
request = urllib.request.Request(url, headers=_request_headers(token))
opener = urllib.request.build_opener(_NoRedirect())
parsed_download = urllib.parse.urlsplit(download_url)
parsed_api = urllib.parse.urlsplit(api_url)
encoded_name = urllib.parse.urlencode(
        {"name": artifact_name, "per_page": 100},
    )
f"{api_url}/repos/{urllib.parse.quote(owner, safe='')}/"
f"{urllib.parse.quote(name, safe='')}/actions/artifacts?{encoded_name}"
request = urllib.request.Request(url, headers=_request_headers(token))
opener = urllib.request.build_opener(_NoRedirect())
parsed = urllib.parse.urlsplit(location)
redirected = urllib.request.Request(
        location,
        headers={"User-Agent": _USER_AGENT},
    )
with urllib.request.urlopen(redirected, timeout=60) as response:
self._session = requests.Session()
response = requests.post(
                    "https://openrouter.ai/api/alpha/decisions",
                    headers={
                        "Authorization": f"Bearer {key.strip()}",
                        "X-OpenRouter-Title": "CodeNi …
with requests.request(
            method,
            f"https://openrouter.ai/api/v1/{path}",
            headers=headers,
            json=payload,
            timeout=(5, 20),
            allow_redirects=False,
            stream=True, …
import urllib.request
with urllib.request.urlopen(url, timeout=1.0) as response:

Why it matters: Usually legitimate, but confirm the destinations are expected and no sensitive data leaves.

Fix: Confirm the destination hosts are expected and that no sensitive data is sent off-host.

CapabilityMCP tool surface detectednot scored · severity lowST-MCP-DETECTED

An MCP tool surface (manifest or tool definitions) was found.

Why it matters: Just context — review which tools it offers and their permissions.

Fix: Review the declared MCP tools and their permissions.

How attackers abuse these capabilities

Interactive labs on the attack class behind the rules above. They show the technique, not anything found in CodeNib MCP server.

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