What is shift-left security?

Vulnerability exploitation has become the primary cause of cyberattacks, accounting for 40% of incidents observed by the IBM X-Force team, according to the 2026 X-Force Threat Intelligence Index. “Security leaders need to shift to a more proactive approach,” said Mark Hughes, Global Managing Partner for Cybersecurity Services at IBM, in a press release on the Threat Intelligence Index. A shift-left strategy transforms cybersecurity from reactive to proactive mode, making it a priority rather than an afterthought.

Shifting security left is built into the secure software development lifecycle (SSDLC), weaving security into every stage of software development. It’s also a key best practice for DevSecOps, which automates the integration of application security (AppSec) and infrastructure security into DevOps processes.

Shift-left security helps lessen security risks, catching them sooner before they escalate. It consists of these core practices:

• Threat modeling

• Secure coding

• Security testing

• CI/CD integration

• Security as code

Threat modeling happens during the design phase. It involves identifying and assessing potential threats to a system and outlining actions to mitigate or prevent them.

The process starts with analyzing the system’s architecture, finding access points and mapping data flows. Next, threats are ranked according to severity to determine which to prioritize. Controls or safeguards are then laid out to manage threats. The resulting threat model can be refined throughout the SDLC.

Modeling threats entails different techniques, such as the STRIDE methodology and the MITRE ATT&CK framework. The Open Worldwide Application Security Project (OWASP) provides more guidance on threat modeling.

Secure coding practices encompass defensive programming strategies that bolster source code against cyberattacks. These include:

• Adding security as part of code reviews

• Authentication and authorization to verify an entity’s identity and grant them the right level of access

• Coupling parameterized queries with prepared statements to prevent SQL injection attacks

• Robust logging and secure error handling mechanisms

• Server-side validation and sanitization of inputs and output encoding to protect against injection attacks

• Strong cryptographic protocols to safeguard data availability, confidentiality and integrity

Comprehensive security testing validates security measures embedded into source code. Unlike shift-left testing, which aims to improve code coverage and code quality, security testing focuses on the application as a whole to surface security issues.

Here are common types of security testing:

• Static application security testing (SAST): Also called “white box” testing, SAST scans code without running the application. It applies predefined rules to flag security flaws.

• Dynamic application security testing (DAST): Often referred to as black box testing, DAST evaluates apps as they’re running. It uses simulated attacks to mimic real-world threat actors.

• Interactive application security testing (IAST): IAST assesses both code context and runtime behavior to report vulnerabilities in real time.

These methods can be combined for a fuller picture of likely vulnerabilities.

Security automation can be built into continuous integration/continuous delivery (CI/CD). Some techniques to incorporate security into CI/CD pipelines include:

• Implementing pre-commit hooks that require secret scanning before developers initiate pull requests and block changes that contain hardcoded secrets (such as API keys, connection strings and other credentials)

• Scanning infrastructure as code (IaC) for misconfigurations

• Secrets detection for artifacts, build logs and environment variables to uncover any exposed secrets before they reach production

• Software composition analysis (SCA) to examine open-source libraries and components, generate a software bill of materials (SBOM) and compare that against databases of known security vulnerabilities

• Vulnerability scanning for container images of cloud-native applications

Like policy as code, security as code treats security rules and policies as executable logic. Automated checks can be run before developers commit code changes to make sure they adhere to security rules and policies.

Security as code lives in the same version control systems that software engineering teams use to manage code. This means code-based security policies can be broadly applied in a repeatable and scalable manner, and any updates can be easily reviewed and tracked.

Shift-left security helps decrease an organization’s attack surface while still maintaining software quality. When enterprises adopt shift-left security, they gain these advantages:

• Enhanced team culture

• Increased customer satisfaction

• Reduced costs

• Swifter releases

Shift-left security fosters collaboration between developer, DevOps and security teams. They share security knowledge and best practices, eliminating information silos. And they agree on security goals, working together to build more secure software.

Moving security sooner in the development lifecycle prevents major exploits from reaching production and negatively impacting users. It also limits the downtime that accompanies emergency fixes or patches for breaches. This allows teams to deliver high-quality, reliable, safe and stable systems, which in turn helps boost customer trust.

Detecting vulnerabilities during the later phases of the SDLC can result in costly reworks. When caught early, security issues become less costly to fix.

Shift-left security avoids bottlenecks that arise from delays in finding vulnerabilities toward the end of the development process, leading to faster delivery cycles. Meanwhile, incorporating shift-left security seamlessly into the SDLC helps streamline workflows, while automated testing and automation as part of CI/CD pipelines contributes to quicker releases.

Shift-left security contributes to enhancing a company’s overall security posture. Here are some tips that can help teams as they implement shift-left security:

• Establish clear security requirements and policies

• Start small

• Embrace automation

• Prioritize based on severity

• Couple shift-left with shift-right

• Refine over time

• Education is key

The planning and analysis phases of the SDLC must define security requirements and policies alongside functional and other project requirements. This is the time to bring in cybersecurity teams, who offer crucial guidance and support along the way.

Shifting security left can be overwhelming, especially for large software projects. Starting small and simple can make the process more achievable. This can look like applying a particular secure coding practice, for example, or piloting security testing for a minor feature.

Automation serves as a vital asset when it comes to shift-left security. For instance, Red Hat Advanced Cluster Security for Kubernetes is a Kubernetes-native security platform that secures containerized apps across their full lifecycle—from build and deploy to runtime. It allows for automatic scanning of container images for misconfigurations and known vulnerabilities. It can also enforce security policies automatically, such as block builds or halt deployment pipelines if an image fails automated checks.

As teams put shift-left security into action, they might encounter alert fatigue from the numerous alerts produced by the tools they use. Creating a triage system can help, with high-risk issues solved before low-risk ones.

Blending both strategies can lead to safer, stronger software. While shifting left spreads security throughout the SDLC, shifting right defends against evolving security threats in production, making them complementary techniques.

Examples of shift-right security include runtime application self-protection (RASP), which detects and responds to attacks in real time, and web application firewalls (WAFs) that monitor web traffic to apps and block malicious traffic as determined by security policies.

Shift-left security is an ongoing, iterative methodology. Companies can apply what they’ve learned over time to continuously improve their approach.

Businesses must include shift-left security as part of a development or DevOps team’s security training. Teams must understand why shifting security left is important, how to implement it and how to use the necessary tools.

As generative AI becomes increasingly integrated into software development workflows, it can also help secure those workflows.

For instance, IBM Bob, an AI-powered development partner, is built on security-first principles and embraces the shift-left philosophy. It has a built-in Review workflow that analyzes code changes and flags potential security issues before developers commit their work. Teams can create a security-focused code review skill that checks source code for common vulnerabilities and adherence to secure coding practices.

Taking it a step further, Bob can generate secure code with an actor-critic workflow. An actor subagent writes security-compliant code according to configured security rules, while a critic subagent validates the code against published security standards.

Meanwhile, IBM Concert® is an agentic IT Ops platform that proactively surfaces security risks early before they escalate into production issues. Concert Protect employs AI-driven vulnerability management to prove which vulnerabilities matter and coordinate remediation.