A guide to modern vulnerability scanning

Every line of code in your application could potentially harbor a bug that attackers can exploit. Multiply that across thousands of dependencies, libraries, and frameworks, and you start to see why regular vulnerability scanning has become non-negotiable for modern software development.

Vulnerability scanning is one critical piece of a broader security strategy, and understanding exactly what it can and can't do matters if you want to actually reduce risk rather than just check compliance boxes.

This guide explains how vulnerability scanning works, where it fits into your security posture, the types of scans available, and how to get the most value from your scanning tools without drowning your team in alert fatigue.

What is vulnerability scanning?

Vulnerability scanning is the automated process of identifying security weaknesses in your software, infrastructure, and systems before attackers do. Think of it as a systematic health check that compares your code, dependencies, and configurations against known security flaws cataloged in public databases.

When researchers discover a security flaw, it receives a CVE identifier (like CVE-2024-1234) through the Common Vulnerabilities and Exposures (CVE) system. Scanning tools then parse your applications and flag anything that matches known vulnerabilities, enabling detection of the same issues across different environments.

Vulnerability scanners examine your software components and cross-reference them against databases such as the National Vulnerability Database (NVD). Maintained by the National Institute of Standards and Technology (NIST), the NVD contains detailed information on known vulnerabilities, including severity ratings and those vulnerabilities potential impacts.

Modern vulnerability scanners can examine multiple layers of your technology stack for particular types of vulnerabilities:

• Networks and endpoints: Routers, firewalls, servers, and workstations for misconfigurations, open ports, and outdated operating system patches

• Web applications: Custom code and web servers for common security flaws like SQL injection and cross-site scripting (XSS)

• APIs: REST and GraphQL endpoints for authentication issues, sensitive data exposure, and input validation problems

• Cloud infrastructure: Cloud-based resources and configurations across AWS, Azure, and GCP

• Containers and images: Container layers and dependencies for known CVEs and security weaknesses

• Open-source dependencies: Third-party libraries and frameworks in your software supply chain

• IoT devices: Connected devices and embedded systems for security vulnerabilities and outdated firmware

Why vulnerability scanning matters

According to the 2025 Verizon Data Breach Investigations Report, exploitation of vulnerabilities remains one of the top pathways for cyberattacks and data breaches. Researchers discover new vulnerabilities daily, and attackers have automated their exploitation efforts to the point where the window between disclosure and active exploitation keeps shrinking.

Without regular scanning and remediation, organizations expose themselves to several critical risks. Compliance becomes impossible since frameworks like PCI DSS, HIPAA, and FedRAMP explicitly require ongoing vulnerability assessment. Engineers waste time tracking down vulnerabilities reactively after incidents, rather than catching them early when fixes are cheaper. Your attack surface expands silently as each new dependency or cloud resource potentially introduces vulnerabilities.

Starting with a secure foundation changes the equation. When you reduce vulnerabilities upstream (for instance, by using minimal, hardened base images), your scanning tools produce cleaner results with fewer false positives and less noise. This shift left makes scanning far more effective and less burdensome for your security teams.

How does vulnerability scanning work?

Vulnerability scanning follows a systematic process: scanners examine your code and dependencies, compare them against databases of known vulnerabilities, and generate reports showing what needs fixing. Here's how that process unfolds in practice:

Scope definition: Teams identify what needs scanning (internal application code, third-party dependencies, container images, infrastructure configurations, or all of the above). The key decision is determining which assets pose the most risk and should be prioritized.

Tool selection and configuration: Different types of vulnerability scans require different tools:

• Static Application Security Testing (SAST) analyzes source code without executing it

• Software Composition Analysis (SCA) identifies vulnerable open-source components in your software supply chain

• Dynamic Application Security Testing (DAST) tests running applications by simulating attacks

• Infrastructure scanning examines network devices, servers, and cloud configurations

Many organizations use multiple scanners to cover their complete attack surface.

Automated analysis: The scanner examines your software in various forms (source code, compiled binaries, running processes) and compares findings against vulnerability databases. Modern standard practice is to integrate this automatic process into CI/CD pipelines.

Report generation: Scanners produce detailed reports listing identified vulnerabilities, including severity ratings based on the Common Vulnerability Scoring System (CVSS), which scores vulnerabilities from 0 to 10. You'll also see CVE identifiers that link to public vulnerability records, a list of affected components showing exactly which dependencies contain the flaw, and remediation guidance suggesting specific patches or updates to apply.

Triage and remediation: Security teams and developers review scan results together. They validate findings to rule out false positives, then assess actual risk based on how your application uses the vulnerable component. From there, they prioritize remediation efforts based on business impact. Teams apply patches or implement workarounds for high-priority issues and document decisions for vulnerabilities that won't be immediately fixed.

Verification scanning: After addressing issues, teams run follow-up scans to confirm vulnerabilities have been properly mitigated, closing the loop and ensuring fixes actually worked.

Types of vulnerability scans

Vulnerability scans differ along three main dimensions: who can access what (authenticated versus unauthenticated), where you're scanning from (internal versus external), and what layer of the stack you're examining (network versus application). Understanding these distinctions helps you build a comprehensive security testing strategy:

Authenticated vs. unauthenticated scans: Authenticated scans use valid credentials to log into systems, providing deeper visibility into vulnerabilities that only appear to logged-in users. Unauthenticated scans examine systems from an outsider's perspective, seeing only what an attacker without credentials would see. Most organizations run both types to get complete coverage.

Internal vs. external scans: Internal scans run from inside your network perimeter, checking for vulnerabilities in systems that aren't directly exposed to the internet. External scans probe your public-facing systems from outside your network, simulating how external hackers see your infrastructure.

Network vs. application scanning: Network scanning focuses on infrastructure components such as routers, firewalls, and servers, looking for issues like open ports and misconfigured services. Application scanning examines software code and application security, identifying issues such as injection flaws, broken authentication, and insecure dependencies.

Best practices for vulnerability scanning

Getting value from vulnerability scanning requires thoughtful implementation:

Integrate scanning into CI/CD pipelines: Automate scans at every stage (code commit, pull request, build, and deployment). This shift-left security model catches vulnerabilities before they reach production when fixes are cheapest.

Scan continuously, not just periodically: New vulnerabilities are disclosed constantly. However tempting it might be to schedule scans with other long-running maintenance tasks,a monthly scan leaves a 30-day window where you're vulnerable without knowing it. Continuous or daily scanning reduces this gap significantly.

Establish clear remediation workflows: Define who triages findings, how quickly findings of different severities must be addressed, and what documentation is required. For critical vulnerabilities, establish SLAs such as "patch within 24 hours" to ensure urgent issues receive immediate attention.

Prioritize vulnerabilities based on context: Not every critical-severity CVE poses a critical risk to your organization. Consider whether the vulnerable code path is actually executed, if the vulnerable component is exposed to untrusted input, what the business impact would be if exploited, and whether compensating controls are in place.

Start with secure foundations: Reducing vulnerabilities at the source makes scanning more effective. When you build on minimal, hardened base images that start with zero known CVEs, your scanners spend less time flagging inherited vulnerabilities and more time catching issues in your actual code.

Measure and improve: Track metrics such as mean time to remediate by severity level, the percentage of vulnerabilities caught in development versus production, the false-positive rate over time, and trends in total vulnerability count. These metrics help you understand whether your vulnerability management program is actually reducing risk.

Challenges and limitations of vulnerability scanning

Vulnerability scanners are powerful tools, but they have clear boundaries. Scanners only catch known, documented issues. They struggle with context. They generate noise that can overwhelm teams. Here's what that means in practice:

Reliance on known vulnerabilities: Scanners only detect CVEs and other publicly documented security flaws. They don't discover zero-day vulnerabilities or novel attack patterns. This is why vulnerability scanning works alongside penetration testing, where security experts manually probe for undiscovered weaknesses.

False positives and false negatives: False positives waste time and create noise, while false negatives create false confidence. Research shows that vulnerability scanners can miss up to 30% of known vulnerabilities, depending on how software is packaged and scanned.

Context and configuration gaps: Many vulnerabilities only matter under specific circumstances. A scanner might flag a SQL injection vulnerability in code that's never exposed to user input. Scanners often lack the context to make these distinctions, leading to over- or under-reporting.

Alert volume and fatigue: Recent research indicates that organizations are drowning in an overwhelming volume of security alerts, and vulnerability scanners contribute significantly to this noise. When teams are inundated with alerts, they start ignoring notifications or burn out from triage exhaustion. Scanning smarter and reducing the vulnerability surface upstream helps address this challenge.

How vulnerability scanning fits into vulnerability management

Scanning is only one component of management! Vulnerability management is the continuous process of identifying, evaluating, treating, and reporting on security vulnerabilities across your systems. An effective vulnerability management program includes asset inventory, regular vulnerability scanning, risk assessment, prioritization frameworks, remediation processes with defined SLAs, verification that fixes worked, and reporting metrics. Vulnerability scanning automates the detection piece, while human judgment drives the rest.

Vulnerability scanning and penetration testing serve different purposes in your security program. Scanning is automated, continuous, and broad (it checks known vulnerabilities across your entire environment using databases of documented security flaws). Penetration testing is manual, periodic, and deep (security experts actively try to exploit vulnerabilities to understand real-world attack paths). Most organizations need both.

How Chainguard transforms vulnerability management

Traditional vulnerability management is a reactive cycle: scan, find hundreds of CVEs, scramble to patch, repeat. This approach burns engineering time and never quite catches up. Chainguard flips this model by providing a secure foundation that dramatically reduces vulnerabilities at the source.

Chainguard Images start as minimal, hardened container images built specifically for security. Every image ships with zero known CVEs at release, giving you a clean baseline. When new CVEs are disclosed, Chainguard rebuilds and publishes updated images within hours. Images contain only what's necessary to run your application, eliminating unnecessary packages that introduce vulnerabilities. Every image includes cryptographically signed attestations, so you know exactly what you're running.

When you build on Chainguard Images, your vulnerability scanner results change dramatically. Fewer inherited CVEs mean cleaner reports and easier triage. Updating to a new Chainguard base image often resolves multiple vulnerabilities in one change. Your security teams spend time addressing application-specific risks rather than managing operating system patches. Maintaining low CVE counts becomes achievable rather than aspirational.

Chainguard's approach to CVE remediation addresses a fundamental problem: most container images accumulate vulnerabilities over time because upstream maintainers don't prioritize security updates. Chainguard's rebuild process ensures you always have access to patched versions.

Chainguard Images integrate with your existing security tools while advancing your security posture through SBOM generation (every image includes a Software Bill of Materials), transparent security advisories, compliance support for FedRAMP, PCI DSS, and other frameworks, and seamless CI/CD integration.