Web app security can sound like a topic for specialists, but the main picture is simpler than many people expect, and there is good news in it. In Verizon's 2026 Data Breach Investigations Report (DBIR), 31% of breaches started with attackers using a flaw in software. That made it the most common single way into a system, ahead of stolen passwords.
That figure covers all kinds of organizations and systems, not only web apps. Even so, it points to something useful if you run a web app: the most common way in is a flaw in software, and flaws in software can be fixed.
What the 31% figure tells you
The DBIR studies confirmed breaches from around the world. A breach is a case where someone gets into a system or its data without permission. The report also looks at how the attackers first got in, and the 2026 edition covers incidents from November 2024 to October 2025. In that period, flaws in software were the most common starting point.
A vulnerability is a weakness in software that someone can use in a way its makers never planned. Once the weakness is known, the people who maintain the software usually publish an update that closes it.
The US Cybersecurity and Infrastructure Security Agency (CISA) keeps a public list of known exploited vulnerabilities, which are flaws that attackers have actually used. A flaw goes on this list only when this is confirmed and when there is a clear way to deal with it, for example an update from the software maker. So every entry on the list comes with a clear next step for the organization affected.
This is the encouraging part. Much of the work that reduces this risk is routine, and routine work is something a business can plan, schedule and budget for.
It is also fair to say that no approach removes risk completely. Verizon's findings show that stolen passwords and phishing are still among the frequent causes of breaches too, so keeping software current works best as one part of a wider set of habits.
Where vulnerabilities come from in a web app
A web app is rarely one block of code. It usually combines your own code, a framework, which is a ready-made base that developers build on, and many dependencies. Dependencies are ready-made pieces of code written by other people, for things like logins, payments or reports.
It is a bit like a house built from ready-made parts, such as doors, windows and locks. Each part comes from a different maker, and any maker can announce a problem in their part later, together with a fix.
A new vulnerability can be found in any of these parts at any time, even long after your app went live. Your own code may stay the same, but what people know about the parts it depends on keeps growing.
Information about known vulnerabilities is public, so a steady routine of updates usually works better than a big effort every few years. When updates are skipped for a long time, the result is outdated dependencies, and catching up takes more work and costs more the longer it waits.
What good web app security looks like in practice
The habits that reduce this risk are simple and well known. Verizon's DBIR page lists keeping software updated and testing security defenses regularly among the basic measures, together with using a second step when logging in and training employees. For a web app, this comes down to four routines.
Keep the parts of your app up to date
Regular updates to the frameworks and dependencies your app uses close known gaps before they cause problems. A steady rhythm, for example every month, is easy to plan, and each update can be tested before it goes live.
Fix the most urgent issues first
Not every vulnerability is equally urgent. CISA recommends starting with the flaws attackers are already using, and its public list makes these easy to check. The fix usually comes as a security patch, which is a small update for one specific flaw.
Have someone review the app on a schedule
A software audit is a review of your software by an experienced engineer. It gives you a fresh view of your code, the parts it depends on and your security basics. It can be useful to schedule one, for example once a year or before a major release.
Keep watching between reviews
Monitoring tools watch your app all the time and alert you when something breaks or behaves in an unusual way. Automatic checks can also warn you when one of the parts your app depends on has a newly found flaw. That way, small issues get attention early instead of waiting for the next review.
When it makes sense to take a closer look
A closer look is useful in a few common situations. The app may have been built over several years by different developers, or nobody may have checked the parts it depends on since launch. It may hold customer or business data that matters. You may also be preparing for growth, for connecting the app to another system, or for a conversation with an investor or buyer, where technical due diligence is likely to come up.
None of this means something is wrong. A review turns guesses into facts, and facts are easier to plan around. The result is usually a clear list of what is fine, what carries risk, and what to address first.
Some teams handle updates and fixes themselves, and others prefer to have support from outside. Both approaches work, as long as someone is clearly responsible for the routine and it actually happens.
At Rocksoft, a Code Audit is a practical way to find these gaps. An experienced engineer reviews your code, including security risks and the ready-made parts from other people that it uses. Then we walk you through, in plain language, what carries risk and what to fix first.
Software Maintenance then helps keep those gaps closed, with regular updates to the parts your app uses, security fixes, automatic checks for known flaws and monitoring, so that known issues do not come back.
