Anthropic and OpenAI just exposed SAST's structural blind spot with free tools
OpenAI recently made a significant move in the application security market with the launch of Codex Security on March 6. This move came just 14 days after Anthropic disrupted the market with Claude Code Security. Both tools utilize LLM reasoning instead of traditional pattern matching, highlighting the limitations of traditional static application security testing (SAST) tools. The entrance of these reasoning-based vulnerability scanners into the market has put the enterprise security stack in a challenging position.
Anthropic and OpenAI independently released their reasoning-based scanners, both identifying bug classes that were previously undetectable by pattern-matching SAST tools. With a combined private-market valuation exceeding $1.1 trillion, the competitive pressure between the two labs ensures that detection quality will improve rapidly. While neither Claude Code Security nor Codex Security is meant to replace existing security tools, they do change the procurement landscape permanently. Currently, both tools are free for enterprise customers, leading to a shift in budget allocation within the cybersecurity space.
Anthropic and OpenAI arrived at the same conclusion using different architectures. Anthropic’s Claude Code Security found over 500 high-severity vulnerabilities in production codebases, while OpenAI’s Codex Security identified critical findings in popular repositories. The evolution of these reasoning-based scanners signifies a shift in the way vulnerabilities are detected and addressed in modern software development.
However, it is essential to note that both tools have limitations. Checkmarx Zero researchers found that moderately complex vulnerabilities could sometimes evade detection by Claude Code Security. Developers could potentially manipulate the scanner into ignoring vulnerable code, indicating a potential detection ceiling. It is crucial for security teams to prioritize patches based on exploitability rather than relying solely on CVSS scores.
Vendor responses to the emergence of reasoning-based scanners have been varied. Snyk acknowledged the technical breakthrough but emphasized the importance of fixing vulnerabilities at scale without introducing new security risks. Cycode CTO Ronen Slavin highlighted the probabilistic nature of AI models and stressed the need for consistent, reproducible results in security scanning.
As security teams navigate the evolving landscape of application security, it is essential to take certain actions before the next board meeting. Running both Claude Code Security and Codex Security against a representative codebase subset can provide insights into blind spots in the existing security stack. Establishing a governance framework and mapping areas not covered by the reasoning-based scanners are also critical steps.
Quantifying the exposure to dual-use vulnerabilities, preparing a board comparison, tracking the competitive cycle, and setting a 30-day pilot window for testing both tools can help organizations make informed decisions about their security posture. The rapid advancements in reasoning-based scanning tools emphasize the need for a proactive and diverse approach to application security.
In conclusion, the emergence of Anthropic’s Claude Code Security and OpenAI’s Codex Security signifies a significant shift in the application security landscape. By leveraging LLM reasoning, these tools offer a new perspective on vulnerability detection and remediation. Security teams must adapt to these changes by integrating reasoning-based scanners into their existing security stack and prioritizing proactive measures to enhance their overall security posture.
