On an almost daily basis, I see new Static Application Security Testing (SAST) tools emerging. Nearly all of these new solutions are powered by LLMs and offered exclusively as SaaS products.
Security is not a trivial matter. High-quality security tools are essential to protect your organisation. What is far more dangerous, however, are professional-looking cybersecurity tools that claim to deliver robust protection but, in reality, provide poor results. Tools of low quality do not just fail to protect you — they create a false sense of security. And that risk is enormous.
A serious SAST scanner for Python must meet certain minimum requirements. Any credible Python security testing tool should, at the very least, satisfy the following criteria:
- FOSS-licensed
The product must be released under a valid Free and Open Source Software (FOSS) licence, ideally one approved by the Open Source Initiative (OSI). Transparency in security tooling is not optional — it is fundamental. - Local-first deployment
The tool should run locally or on a server within your own security perimeter. SaaS-only solutions, where you have no control over the execution environment or the handling of your source code, should be avoided. Your code should remain under your control at all times. - Actively maintained
The project must be actively maintained and demonstrate a consistent level of quality. This includes regular updates, responsible vulnerability handling, and visible issue management. - Public version control repository
The source code must be publicly available in a version-controlled repository with a clear, verifiable URL. Without transparent development practices, trust is impossible.
If a Python SAST tool does not meet these basic standards, it should not be entrusted with the security of your codebase.
Ideally, all FOSS cybersecurity projects should also comply with the minimum requirements defined by the OpenSSF Best Practices Badge Program. Security tools must not only claim quality — they should be able to demonstrate it against recognised industry standards.
A Python-specific SAST scanner is fundamentally different from a generic SAST solution that attempts to analyse multiple languages such as C, C++, or Java. General-purpose SAST tools frequently overlook vulnerabilities that are specific to Python. Python has its own unique syntax, semantics, and language constructs. Only scanners designed specifically for Python can reliably and comprehensively identify security weaknesses in Python code.
The Python Standard Library provides extensive functionality for common programming tasks. However, some modules within the standard library must be used with caution from a security perspective. A dedicated Python SAST tool understands these nuances and can highlight potentially unsafe usage patterns before they become real vulnerabilities.
Selecting a high-quality SAST tool for Python should not be difficult. Most organisations already rely on internal evaluation checklists — so use a robust and well-defined checklist when assessing your security tools.
In many mature professions, checklists are mandatory because they significantly reduce the likelihood of disaster. Aviation, surgical medicine, and engineering disciplines — including the automotive and rail industries — all depend on structured checklists to prevent catastrophic failures.
Cybersecurity should be no different. When the integrity of your codebase is at stake, disciplined evaluation is not optional — it is essential.
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