Break your scanner before attackers do.
1,312 adversarial attack patterns from MCPTox, Unit42, and CyberArk research. Mutation, fuzzing, chain attacks, and SARIF reporting — all from a single CLI.
Install
pip install mcp-stress-test
Stress
mcp-stress stress run
--phases baseline,mutation
Fuzz
mcp-stress fuzz evasion
-p "Read SSH keys" --use-llm
Features
Offensive security for MCP tool ecosystems.
1,312 attack patterns
Three paradigms from MCPTox: direct injection, semantic blending, and cross-tool poisoning. Ready to fire out of the box.
LLM-guided fuzzing
Deterministic mutations plus LLM-guided evasion discovery. Find the payloads your scanner misses.
Multi-tool chains
Data exfiltration, privilege escalation, and persistence chains that test detection across coordinated attacks.
Usage
CLI
# Stress test your scanner
mcp-stress stress run \
--phases baseline,mutation,temporal
# Compare detection before/after
mcp-stress scan compare \
-t read_file -s obfuscation
# Execute attack chains
mcp-stress chain execute \
-c data_exfil_chain Python API
from mcp_stress_test import PatternLibrary
from mcp_stress_test.generator import SchemaMutator
from mcp_stress_test.chains import ChainExecutor
library = PatternLibrary()
library.load()
mutator = SchemaMutator()
for case in library.iter_test_cases():
result = mutator.mutate(
case.target_tool,
case.poison_profile.payloads[0]
) Mutation Strategies
Escalating sophistication to probe scanner limits.
Research-Backed
Built on cutting-edge MCP security research.
MCPTox benchmark
1,312 patterns across 3 attack paradigms — the largest public MCP poisoning dataset, from arxiv 2508.14925.
Palo Alto Unit42
Sampling loop exploits and tool-shadowing attacks from production MCP deployment research.
CyberArk
Full-schema poisoning where no output field is safe — descriptions, error messages, return values.