B — Some risk signals Graded October 16, 2026Minor concerns worth a quick check.Based on public adoption and transparency signals as of October 16, 2026. Our opinion, not a code audit or security guarantee.
AI agent skill · General
skill-scanner
Security Scanner for Agent Skills
Bottom line: Signal-based grade (4/7 points): well starred on GitHub, listed in several sources, public source code. This reflects adoption and transparency, not a code audit.
- Popularity score
- 47/100
- Rank
- Not ranked: outside the 500 most popular tools
- GitHub stars
- 2.6k
What it does
skill-scanner is a security analysis tool that scans AI agent skills and capabilities for vulnerabilities, misconfigurations, and potential security risks. It helps identify whether agent skills are safe to deploy by checking for common security patterns, privilege escalation paths, and unintended data exposure.
Who it’s for
Security teams, AI platform engineers, and builders deploying multi-agent systems who need to audit skills before production. Organizations running Claude, OpenAI, or other AI agent frameworks with custom skill integrations.
Copy-paste setup
Check these steps against the project’s own instructions before running anything.
Verify against the repo README at https://github.com/cisco-ai-defense/skill-scanner (opens external site) for the latest installation method. The tool appears to be Python-based; typical setup likely involves pip install skill-scanner or cloning the repository. Exact configuration for your agent framework (e.g., Claude Desktop config.json) should be confirmed in the official documentation.
Risks
- Credential scope exposure: Scanning skills may require read access to agent configs, skill definitions, or environment variables; ensure scanner itself doesn't over-privilege
- Incomplete coverage: Scanner may miss novel attack vectors or framework-specific vulnerabilities if not regularly updated
- False negatives: Security checks rely on pattern matching; sophisticated obfuscation or zero-day skill exploits may evade detection
- Supply chain: Dependency on Cisco's maintenance cadence; security fixes may lag emerging threat disclosures
- Prompt injection via skill definitions: Malicious skill payloads could potentially exploit the scanner itself if it executes or parses skill code unsafely
How to stay secure
Least-privilege permissions
- Run scanner with read-only access to skill definitions and configs; deny write/execute permissions on agent runtime
- Use separate service accounts for scanning vs. agent execution; never share credentials between roles
- Restrict scanner access to specific skill namespaces/directories; avoid blanket read access to all environment variables
- Disable scanner's ability to invoke skills directly; scanning should be static analysis only
Network isolation
- Isolate scanner to a dedicated network segment or container; restrict outbound connections to only package registries and threat intelligence feeds
- Block scanner access to production agent runtime endpoints; use separate staging environment for scanning
- Implement egress filtering to prevent scanner from exfiltrating skill definitions or sensitive metadata to external hosts
Monitoring
- Log all scanner activities: files accessed, checks executed, findings reported; alert on unusual access patterns or repeated scan failures
- Track scanner dependency updates and patch application; correlate with security advisories from Cisco and upstream libraries
- Monitor for scanner crashes or hangs when processing malformed skill definitions; may indicate exploitation attempts
Red flags to watch for
- Skills with inline code execution (eval, exec, dynamic imports) or shell command patterns; prioritize manual code review
- Scanner unable to parse or timeout on specific skills; potential obfuscation or adversarial payload triggering scanner bugs
- Repeated scan false negatives on known vulnerable patterns; indicates stale detection rules requiring immediate update
- Credential artifacts (API keys, tokens, passwords) appearing in skill definitions during scans; escalate to incident response
Alternatives
- Semgrep – Open-source static analysis engine with rules for agent/LLM security patterns; highly customizable
- Snyk – Commercial supply-chain and code vulnerability scanner with some LLM/agent-specific checks
- Checkov – Infrastructure-as-code scanner that can audit agent configurations and IAM policies
- Manual code review + custom guardrails – For high-security deployments, paired with runtime monitoring tools like LangSmith or Arize