How dynamic application security testing validates risk at runtime

Security teams already have long queues of potential application vulnerabilities. The useful question is what happens next: can they see how a weakness behaves in a running application, reproduce the attack, and give developers enough evidence to fix it?

Dynamic application security testing (DAST) helps answer those questions by testing applications as an attacker encounters them. The IDC MarketScape: Worldwide Dynamic Application Security Testing 2026 Vendor Assessment (Doc #US54119126, September 2026). The IDC MarketScape evaluated 16 vendors and named Rapid7 a Leader.

We believe the result reflects the strength of Rapid7’s DAST capabilities, but the IDC MarketScape also offers a useful view of where the category is heading. DAST has developed beyond traditional web scanning into a source of runtime evidence that can help organizations validate risk across the application layer.

From possible weakness to validated application risk

Code analysis and dependency scanning help teams identify weaknesses before an application is deployed. DAST provides a different view by interacting with the assembled application while it is running. It can show what happens when a particular request reaches the application, how the application responds, and whether a suspected weakness can be reproduced.

This is especially valuable for APIs and AI-backed applications, where risk may emerge through interactions among models, prompts, data, tools, and permissions. Some of these behaviors cannot be fully understood from source code or a dependency manifest. They become visible when the application is exercised under runtime conditions.

DAST therefore has a direct role in continuous threat exposure management (CTEM). Discovery gives teams a view of their assets and possible weaknesses, but that view alone does not tell them where to focus. Validation helps narrow the field by showing which exposures can be reached or exploited and providing evidence that teams can use to take action.

For Rapid7, DAST is exposure management applied to the application layer. Web applications, APIs, and AI-backed endpoints are all part of the attack surface, so they need to be discovered, tested, prioritized, and managed alongside infrastructure, cloud, and other exposures.

Why we believe Rapid7 was named a Leader by IDC

Rapid7’s DAST solution is delivered as part of the Exposure Command portfolio. Its scan engine maps an application, executes attacks against the discovered paths, and validates confirmed findings. Security teams can map a broad area of an application while limiting active attacks to an appropriate set of paths, giving them control over how testing is performed.

Findings are checked against Rapid7 telemetry to help determine which issues warrant closer attention. When a finding needs action, browser-based replay reproduces the original request, the attack request, and the triggering response. Developers receive evidence they can work with, rather than a finding they must first spend time proving.

Authenticated scanning can be difficult to maintain across a changing application portfolio, and a broken login sequence can leave important areas untested. Rapid7’s solution can identify the affected step and support a targeted update without requiring the entire sequence to be recorded again.

The connection with Surface Command adds another useful layer. Newly discovered external assets can be surfaced for application testing, helping teams close the gap between finding an application and understanding the risk it presents

DAST plays a core role within Exposure Command: providing the application-layer validation teams need to prioritize risk and move from findings to remediation.

Learn more about Rapid7 Exposure Command.