flawfinder

a program that examines source code looking for security weaknesses

flawfinder v2.0.20 130.6K downloads/30d#11,637 on PyPI

Copyleft license GPL-2.0+ Active released 2026-05-17

What it is and what it does

Flawfinder is a command-line static analysis tool that examines C and C++ source code to detect potential security weaknesses. It works by scanning code without executing it, identifying patterns and constructs known to be security risks, then ranking findings by severity to help developers prioritize fixes.

The tool runs as a standalone Python application with no external runtime dependencies, making it straightforward to integrate into development workflows or security scanning pipelines. It supports Python 2.7 and Python 3, and is classified as production-stable with active maintenance.

Use it for:

Scan legacy C/C++ codebases before security audits to identify and prioritize known vulnerability patterns
Integrate into CI/CD pipelines to flag potential security issues in pull requests before code review
Perform initial security triage on unfamiliar C/C++ projects to understand baseline risk areas
Verify that security fixes have addressed flagged issues in previously scanned code

Worth the install?

AI-flagged interpretation of the facts on this page — verify before relying

Flawfinder scans C/C++ source code to identify potential security flaws and ranks them by likely severity.

Yes, if you maintain or audit C/C++ code. Flawfinder is production-stable, has no install friction, carries no known vulnerabilities, and fills a specific niche in static security analysis. The GPL-2.0+ copyleft license is a consideration for proprietary projects but poses no barrier to open-source use.

Install

flawfinder on PyPI

pip

pip install flawfinder

uv

uv add flawfinder

poetry

poetry add flawfinder

Installing flawfinder

Before you install

Low install friction with no runtime dependencies. Active maintenance status and production-stable classifier indicate ongoing support.

License in practice

Released under GPL-2.0+, a copyleft license. Use is free for open-source projects; proprietary or closed-source use requires careful license compliance review.

Quickstart

pip install flawfinder
flawfinder /path/to/source/code

Verify before relying

Whether the tool integrates with common CI/CD platforms or build systems beyond command-line use
Performance characteristics on large codebases or typical scan times
Specifics of which C/C++ standards or dialects are supported

Package facts

License	GPL-2.0+ (copyleft)
Python support	supports the current Python release (>=2.7)
Install friction	low — pure-Python wheel
Runtime dependencies	none
Maintenance	actively maintained — 89 days since the last release
First released	2017-09-03
Downloads	130,588/month — #11,637 on PyPI (30-day window, as of 2026-08-14)
Known vulnerabilities	none known (OSV.dev, checked 2026-08-14)

Evidence: flawfinder-2.0.20-py2.py3-none-any.whl

Keywords: analysis, security, analyzer

Development Status :: 5 - Production/StableEnvironment :: ConsoleIntended Audience :: DevelopersLicense :: OSI Approved :: GNU General Public License v2 or later (GPLv2+)Natural Language :: EnglishOperating System :: OS IndependentProgramming Language :: Python :: 2.7Programming Language :: Python :: 3Programming Language :: Python :: 3.6Topic :: SecurityTopic :: Software Development :: Build ToolsTopic :: Software Development :: Quality AssuranceTopic :: Software Development :: Testing