Application security remains a persistent weak point for organizations. Some 82% of companies now take more than a year to address their known vulnerabilities, largely due to the rapid adoption of AI-powered development tools and the heavy reliance on open-source components.
In the majority of cases, breaches don’t come from advanced zero-days, but basic security gaps that are easy to fix but remain overlooked. Here are the most common application security issues and how to make sure they don’t haunt you.
Treating Application Security as a Late-Stage Activity
For many teams, security testing is a final checkpoint before release. The problem with that approach is that by the time all the code has been written, vulnerabilities become harder, more expensive, and even impractical to fix.
The sooner issues are detected in the development lifecycle, the easier they are to remediate, as you’ll be less concerned about breaking things or reworking large parts of the application.
A great way to achieve that is by adopting a shift-left approach, where security testing starts early in the development process and becomes a continuous part of the developer workflow rather than a final step. Teams can implement Static Application Security Testing (SAST) into IEDs and CI/CD pipelines to identify and fix vulnerabilities as they write code.
Ignoring Third-Party and Open Source Dependencies
Open-source components make up about 70-90% of modern apps. Developers are heavily reliant on third-party libraries to speed up development, but they often do so without fully understanding the security risks those dependencies might bring.
For that reason, software supply chain attacks are on the rise. In March 2026, attackers compromised the widely used Axios npm package, injecting a malicious dependency that executed a cross-platform remote access trojan during installation. That is just one example of many.
To catch these risks early, organizations need full visibility into their dependency stack. Implementing Software Composition Analysis (SCA) tools allows teams to identify known vulnerabilities (CVEs), detect outdated or abandoned libraries, and flag potentially malicious packages.
Failing to Secure APIs
APIs are an essential part of modern applications, acting as the link between services, systems, and users. With the adoption of microservices and distributed architectures, the number of APIs continues to grow rapidly.
This expansion significantly increases the attack surface, especially since many APIs are directly exposed to the internet and lack proper monitoring or security controls.
API risks are well documented in the OWASP API Security Top 10. Common issues include broken object-level authorization (BOLA), where users can access data they shouldn’t, as well as excessive data exposure and weak authentication mechanisms.
Securing APIs requires more than basic access controls. Strong authentication mechanisms such as OAuth or token-based authentication are essential, but they must be paired with proper authorization checks at the object and function level. In other words, it’s not enough to verify who the user is – you also need to enforce what they are allowed to access.
Overlooking Runtime Security
As modern architectures heavily rely on APIs and dynamic interactions, you can’t assume that the application is secure just because it passes pre-release testing. In reality, no visibility into live application behavior is just as risky as not testing at all.
Vulnerabilities like logic flows and zero-days often surface after deployment with real user interactions and data flows. Even vendors like Microsoft release regular security updates because new vulnerabilities are constantly appearing across their services.
There are several ways to start with runtime security. Dynamic Application Security Testing (DAST) can help identify issues in running applications, while Runtime Application Self-Protection (RASP) provides in-app visibility and blocking capabilities.
Web Application Firewalls (WAFs) and API protections add an additional layer of defense at the edge. Most importantly, teams should continuously monitor application behavior to detect anomalies, abuse patterns, and signs of exploitation in real time.
Poor Integration Between Security and Development Teams
In many organizations, cybersecurity and dev teams operate as completely separate entities. Security teams define policies, run scans, and report findings, while developers are expected to fix issues later in the process.
The result is predictable. Findings take forever to address, or are sometimes ignored or deprioritized, creating friction between teams rather than driving meaningful security improvements.
To address this, organizations need to bring security closer to the development workflow. Embedding security into CI/CD pipelines ensures that vulnerabilities are identified early and continuously.
More importantly, findings should be actionable and prioritized, giving developers clear guidance on what to fix and why it matters.
Conclusion
Application security is not failing because of a lack of tools or because the pace of development is too hard to keep up with. It is failing for the teams that still see it as separate from the development process.
The teams that do succeed aren’t necessarily doing more, they just do it earlier and more consistently. When security is directly embedded into dev workflows throughout the SDLC, issues surface early and are way less likely to impact the application in production.
