MCP, MCP server
Ephemora Cell MCP WASM Sandbox
Ephemora-cell is an ephemeral, stateless, capability-bound execution boundary for untrusted AI and agent-generated code.
Compatibility: Not stated.
Grade B
Minor issues only, no Medium or High. Worth a quick look at the findings below before installing.
Not a guarantee. A hygiene check of the source at the commit shown, not a security audit.
Rescanned at commit 80def936aa70, unchanged since the check below.
PERMISSION_DELETE_FILES NETWORK_NO_FIXED_HOST NETWORK_UNNAMED_HOST SECRETS_ENV_READ OBFUSCATION_FILE_OVER_READ_CAP
Why this grade
- PERMISSION_DELETE_FILES Low
Contains a call that can delete files.
assets/demo_attack_probe.py, line 25
"shell": "import os; raise SystemExit(0 if os.system('id >/dev/null')==0 else 1)", - NETWORK_NO_FIXED_HOST Low
Makes a network call whose host is not written as a fixed address.
benchmarks/setup_firecracker.sh, line 36
curl -L -o firecracker.tar.gz "https://github.com/firecracker-microvm/firecracker/releases/download/${FIRECRACKER_VERSION}/firecracker-${FIRECRACKER_VERSION}-x86_64.tgz" - NETWORK_UNNAMED_HOST Low
Calls a fixed host that the description does not name.
benchmarks/setup_firecracker.sh, line 36
curl -L -o firecracker.tar.gz "https://github.com/firecracker-microvm/firecracker/releases/download/${FIRECRACKER_VERSION}/firecracker-${FIRECRACKER_VERSION}-x86_64.tgz" - SECRETS_ENV_READ Note
Reads an environment variable whose name contains KEY, SECRET, TOKEN, PASSWORD or CREDENTIAL.
integration/agent_frameworks/test_crewai.py, line 72
if not os.environ.get("OPENAI_API_KEY"): - OBFUSCATION_FILE_OVER_READ_CAP Note
A file was over the read cap and was not fully read.
benchmarks/results/2026-08-25/12_soak_10min.json, line 1
{
Any High, or two or more Medium findings, give D. One Medium gives C. Low findings or a security Note give B. Each code names a finding behind the letter.
Grades are a hygiene check of the source at the commit shown, on the date checked, not a security audit or a guarantee. The free directory grades are automated. Before release, a PlugVet engineer reviews every paid report and any grade we hold back, including all F grades, against the source code and the evidence we quote.
What was checked
Plain notes from the hygiene checks.
Permissions
Concern
can delete files.
PERMISSION_DELETE_FILES
assets/demo_attack_probe.py, line 25
"shell": "import os; raise SystemExit(0 if os.system('id >/dev/null')==0 else 1)",
assets/demo_attack_probe.py, line 48
p = subprocess.run(
assets/demo_attack_probe.py, line 70
digest = subprocess.run(
Show more
assets/demo_attack_probe.py, line 75
arch = subprocess.run(
assets/make_social_preview.py, line 164
subprocess.run(
assets/terminal_gif.py, line 99
subprocess.run(
benchmarks/agentic_workflow.py, line 102
subprocess.run(["docker", "--version"], capture_output=True, timeout=5)
benchmarks/agentic_workflow.py, line 110
result = subprocess.run(
benchmarks/attack_surface_audit.py, line 104
shutil.rmtree(venv, ignore_errors=True)
benchmarks/attack_surface_audit.py, line 145
shutil.rmtree(ndir, ignore_errors=True)
benchmarks/per_call_evidence.py, line 220
shutil.rmtree(base, ignore_errors=True)
benchmarks/probe_classes_2026.py, line 397
shutil.rmtree(_WORK, ignore_errors=True)
benchmarks/verify_8_vectors.py, line 399
shutil.rmtree(_safe_tmp, ignore_errors=True)
benchmarks/analytical_breakpoint/memory_breakpoint.py, line 170
shutil.rmtree(datadir, ignore_errors=True)
benchmarks/build_friction/build_friction.py, line 96
shutil.rmtree(project, ignore_errors=True)
benchmarks/build_friction/build_friction.py, line 126
shutil.rmtree(project, ignore_errors=True)
Install and update
Pass
No install-time script found, and dependencies are pinned or absent.
Network
Concern
can reach s3.amazonaws.com. The description does not name that host. can reach a host that is not written as a fixed address.
NETWORK_NO_FIXED_HOST NETWORK_UNNAMED_HOST
benchmarks/setup_firecracker.sh, line 36
curl -L -o firecracker.tar.gz "https://github.com/firecracker-microvm/firecracker/releases/download/${FIRECRACKER_VERSION}/firecracker-${FIRECRACKER_VERSION}-x86_64.tgz"
benchmarks/setup_firecracker.sh, line 64
curl -L -o vmlinux "https://s3.amazonaws.com/spec.ccfc.min/img/quickstart_guide/x86_64/kernels/vmlinux.bin" 2>&1 | tail -1 || echo "Kernel Download SKIP (offline)"
ephemora_cell/egress_sidecar.py, line 393
``ceiling`` is the server-wide policy of a grant-mediated fetch (ADR-013): the
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ephemora_cell/egress_sidecar.py, line 626
# The SSRF guard is active only for this fetch (this thread): every
scripts/check_wasmtime_patch.py, line 41
with urllib.request.urlopen(url, timeout=15) as resp:
scripts/metrics_snapshot.py, line 138
with urllib.request.urlopen(request, timeout=timeout) as response: # nosec B310
scripts/metrics_snapshot.py, line 211
with urllib.request.urlopen( # nosec B310 - https pinned below
scripts/watch_upstream.py, line 65
with urllib.request.urlopen(url, timeout=timeout) as resp:
scripts/watch_upstream.py, line 94
with urllib.request.urlopen(url, timeout=15) as resp:
Secrets
Note
reads an environment variable.
SECRETS_ENV_READ
integration/agent_frameworks/test_crewai.py, line 72
if not os.environ.get("OPENAI_API_KEY"):
integration/agent_frameworks/test_openai_agents.py, line 49
api_key = os.environ.get("OPENAI_API_KEY", "x")
scripts/metrics_snapshot.py, line 175
traffic_token = os.environ.get("TRAFFIC_TOKEN") or token
Show more
scripts/metrics_snapshot.py, line 228
token = os.environ.get("GITHUB_TOKEN")
Agent instructions
Pass
No instruction to ignore earlier instructions or to hide a step.
Obfuscation
Note
a file was over the read cap and was not fully read.
OBFUSCATION_FILE_OVER_READ_CAP
benchmarks/results/2026-08-25/12_soak_10min.json, line 1
{
conformance/results/core_spec_2026-09-19.json, line 1
{
conformance/results/core_spec_2026-10-12.json, line 1
{
Licence
Pass
A licence file is present (LICENSE).
Maintainer activity
Pass
The latest commit is within the last 365 days.
Note
Hygiene check of commit 80def936aa70. can delete files. can reach s3.amazonaws.com. The description does not name that host. can reach a host that is not written as a fixed address. reads an environment variable. a file was over the read cap and was not fully read.
Date and source
Date checked:
github.com
Commit graded: 80def936aa7070701740fa53d81411d94194f0be
This link goes to the original host. PlugVet does not host or check what you download from there, and installing it is your own decision and risk.