Essentially, application programming interfaces (APIs) exist to allow two different software programs to communicate and exchange data with each other. This functionality is key to the modern application ecosystem, leading to 83% of organizations now adopting an API-first approach for mobile, cloud, SaaS, and AI-integrated systems.
With such strong adoption, the question of API security also comes into play, especially considering that APIs handle authentication, payments, personal data, and other critical business workflows.
But despite their importance, research shows that 47% of APIs still skip authentication entirely, indicating a clear lag between API adoption and the essential security controls needed to protect them.
Why APIs Are High-Value Targets for Attackers
At a basic level, an API acts as a data pipeline between independent systems. A client sends a request, the API processes it, and the backend returns data or performs an action. It is an entirely automated action with privileged access to data and business logic. That direct access is exactly what makes APIs so attractive to attackers.
A compromised API allows a bad actor to directly interact with backend systems and send requests to their benefit, whether it’s exfiltrating data or abusing business logic to manipulate accounts, perform unauthorized transactions, or disrupt critical application workflows.
Most API traffic uses HTTPS and otherwise blends in with legitimate application traffic. Unless API-specific monitoring and detection are in place, malicious activity can persist unfettered. But the biggest culprit for API-related incidents remains weak security configuration.
Organizations are still learning how to safely integrate APIs into their workflows, and cybercriminals are taking advantage. In one recent breach, an unmonitored third-party API integration led to the exposure of over 5.6 million credit card details from customers of credit check giant 700Credit.
What ‘Skipping Authentication’ Really Means
According to the OWASP API Security Top 10, risks tied to authentication and authorization failures are the most prevalent and consistently exploited. When we say an API “skips authentication,” it doesn’t always mean there is no security present at all, but it does mean the most fundamental access control is missing, which is verifying who or what is making a request.
Authentication failures can fall into one of three categories: no authentication at all, weak authentication, and broken authorization.
No authentication means that the API accepts requests without verifying identity. This often occurs when internal or development APIs are later exposed externally. Weak authentication is when authentication exists, but relies on insecure or easily abused methods such as static embedded API keys, hardcoded tokens, or long-lived credentials that are rarely rotated.
Broken authorization refers to cases where the API correctly identifies the caller, but doesn’t properly enforce what actions they’re allowed to take, allowing attackers to do way more than they should.
So why do these problems persist? In most cases, it comes down to speed and convenience. Dev teams are under pressure to deliver quickly, and implementing robust authentication and authorization adds complexity. Another factor is that many developers do not view application security as a top priority.
Other Risks Facing APIs
While authentication and authorization failures are the most common, they are not the only API security risks organizations face. OWASP lists several other weaknesses that attackers exploit, often in combination with access control gaps.
Excessive data exposure is right up there. Many APIs return more data than the client actually needs, which may allow attackers to harvest sensitive information. Lack of rate limiting is also common, paving the way for brute-force attacks or disruptions in service availability.
But some of the most damaging API attacks do not exploit technical vulnerabilities at all. Instead, attackers abuse the intended logic of an application. This is called business logic abuse, and it occurs when APIs allow actions the designers did not anticipate.
Further enabling these risks is a lack of logging and monitoring around API integrations, allowing malicious activity to persist for weeks or months without triggering any alerts.
Practical Steps to Improve API Security
Improving API security requires a combination of controls that provide continuous protection throughout the API lifecycle.
A great place to start is placing APIs behind a secure API gateway that acts as the single entry point for traffic. An API gateway can enforce consistent security policies across all endpoints, including rate limiting to prevent brute force and Denial of Service (DoS) attacks.
When it comes to authentication, rather than issuing tokens from scattered modules of an application, use a centralized OAuth 2.0 authorization server to issue and manage access and refresh tokens.
Strong authorization is just as important as authentication. Use token scopes to limit the broad categories of actions a client can perform. API security should assume that no client or network segment is inherently trustworthy. Apply Zero Trust principles by validating every request regardless of origin, enforcing HTTPS/TLS encryption for all API traffic (internal and external), and continuously verifying identity and permissions at every invocation.
One of the biggest risks to API security is a lack of visibility. Implement detailed logging of API requests and responses, and pair this with monitoring and anomaly detection tools that can identify unusual access patterns, such as sudden spikes in requests or attempts to access unauthorized resources.
Conclusion
API security is one of the most important risks organizations are ignoring heading into 2026. API adoption is at an all time high and still growing, while security practices are lagging dangerously behind. The fact that nearly half of API integrations lack basic authentication means that many modern applications remain vulnerable.
Before a breach happens, developers and security leaders must act quickly to address these gaps and ensure the privacy and accessibility of the sensitive data and processes APIs handle.
Working as a cyber security solutions architect, Alisa focuses on application and network security. Before joining us she held a cyber security researcher positions within a variety of cyber security start-ups. She also experience in different industry domains like finance, healthcare and consumer products.
