Open-source software can be safe, but its security depends on how well developers maintain it and how carefully you choose and use it. Public code gives researchers more opportunities to find flaws, while unmaintained projects can leave them unresolved.

Research open-source apps as thoroughly as you would any other software. Look into the project’s maintainers, security history, dependencies, and license to get a feel for whether it’s safe to use.

This guide explains the main benefits and risks of open-source software, what to check before using it, and the steps you can take to use it more safely.

What is open-source software?

Unlike proprietary software, open-source software makes its source code available for people to inspect, modify, and share under the terms of its license. That openness lets developers study how a program works and adapt it to their needs.

The model also changes how software gets developed. A single company may lead a project (e.g., Mozilla with Firefox, Google with Android), or developers from around the world may contribute code, report bugs, and improve it over time. The result depends on the project’s license and community efforts.

Is open-source software the same as FOSS?

FOSS stands for “free and open-source software.” The term combines two ideas: users can check and modify the source code, while the software’s license gives them specific freedoms to use, share, or change it.

People often use “open-source software” and “FOSS” interchangeably, although the terms grew out of different communities, namely the Open Source Initiative and the Free Software movement. “Free” in FOSS refers to freedom, not to whether the software costs money.

Advantages of open-source software

Publicly available code, community involvement, and greater control over the software you use can make open-source software seem safer at first glance, whether you’re a user or a developer. Here’s how.

Transparent code and community expertise

Open source code lets developers and security researchers inspect how software works, which can make flaws easier to find and report. That visibility also lets users review changes instead of relying entirely on a vendor’s claims about security.

Because users can audit and modify the code, they can also fix problems or adapt the software when the original maintainer cannot respond quickly. However, this flexibility only helps when someone has the skills and resources to maintain those changes properly.

Lower licensing costs and greater freedom of choice

Open-source software can be a safer pick from a practical standpoint as well. For one, you reduce licensing costs, which gives you more freedom to choose the tools that make sense for your project. That flexibility can also make it easier to replace software when a vendor stops supporting it.

Having more control over your software can reduce dependence on a single supplier, though security still depends on the alternatives available. Assess each project carefully before switching to it or adding it to your systems.

Open-source software security risks

Open-source software is only safe as long as the developers maintain it and its components don’t get compromised along the way. AI tools have also made it faster for attackers to find weaknesses.

Abandoned projects and vulnerable dependencies

Some open-source projects stop receiving updates while people continue using them. That leaves new vulnerabilities without anyone to fix them, and the problem may be harder to spot if the software still appears to work normally.

Dependencies create another layer of risk. Your software may rely on dozens of external packages, and a vulnerability in just one of them can affect the whole app. Keeping track of those dependencies helps you spot problems sooner.

Security flaws in widely used components

A flaw in a popular open-source component can affect thousands of apps that rely on it. The more widely a component is used, the more systems may be exposed when someone discovers a vulnerability.

These flaws can also contribute to supply chain attacks (e.g., Log4Shell in Log4j or Mini Shai-Hulud in npm), in which attackers target software that other organizations already trust. A compromised component can then introduce security problems into many projects at once.

AI can find vulnerabilities at unprecedented scale

AI tools can now examine code far faster than human researchers, which may help uncover vulnerabilities that remained hidden for years. For instance, researchers at Nebula Security used their AI-driven VEGA platform to discover GhostLock (CVE-2026-43499), a Linux kernel vulnerability that had gone undetected for 15 years.

This is just one example in a series of Linux kernel vulnerabilities disclosed in 2026. As AI systems become more capable, attackers may gain better tools to find and exploit flaws that have remained hidden in widely used open-source software.

What to check before using open-source software

Before adding FOSS to a personal or company project, it’s worth asking yourself a few basic questions about the software. These can help you decide whether the software is safe and a good fit for your needs.

Is the code being actively maintained?

Look beyond the last release and check whether developers still fix bugs, review changes, and publish updates. A project with regular activity is more likely to receive fixes when new problems arise, while long periods without updates may make the software less reliable in the long run.

Who maintains the project?

Look at the people and organizations behind the project. A single developer may maintain a useful tool, but it may not have much staying power. Meanwhile, a larger team or company may provide more resources for ongoing development and security fixes.

Is the community active and responsive?

Look at how users and developers interact when someone reports a problem. Recent discussions, helpful replies, and resolved issues can show that people still use the software and take problems seriously.

Has the software undergone security audits or reviews?

For software that handles sensitive data or supports important systems, look for independent audits or documented security reviews. These sources can show whether researchers have examined the software and how maintainers responded when they found problems.

What license does the project use?

Check the software’s license before using it to avoid legal problems later, especially when combining several open-source components. Common license types include:

  • Permissive licenses: Allow broad use, modification, and redistribution with relatively few conditions. Examples include MIT, Apache 2.0, and BSD licenses.
  • Copyleft licenses: Things like GPL and AGPL require certain modifications and redistributed versions to remain under the same license.
  • “Weak copyleft” licenses: Developers can combine the licensed code with other software while imposing specific conditions on how modifications are shared. The MPL and EPL licenses fall under this category.

How to use open-source software safely

Using open-source software safely means keeping track of what you install, where it comes from, and how often you update it. The following tips can help you catch problems before they affect your systems:

  • Use trusted package managers and repositories: Install software through trusted sources whenever you can, since they help reduce tampering and make version tracking easier over time.
  • Verify software before installing: Check the file’s signature or checksum before you run it, so you can catch altered downloads and confirm that the copy matches the one the developer published.
  • Maintain an inventory of your FOSS dependencies: Keep a list of the open-source tools and libraries you use, along with their versions, so you can tell quickly whether a new issue affects your setup.
  • Keep your software up to date: Follow project releases and apply security updates without unnecessary delays. Regularly reviewing updates means you won’t rely on versions with known flaws.
  • Scan dependencies for known vulnerabilities: Security scanners can check your dependencies against databases of known vulnerabilities and flag affected versions. This helps you find problems before deployment.
  • Create guidelines for using open-source software: Set clear rules for which components your teams can use, how they should be reviewed, and who handles updates. This keeps unapproved software from entering your systems unnoticed.
  • Support the open-source projects you use: Report bugs, improve docs, or send fixes when you can, because steady user support helps projects stay active and easier to trust.

Is open-source software safe? FAQs

Can you trust open-source software?

Open-source software lets you inspect what it does, but you still need to check who maintains it, how often it gets updates, and whether it has undergone security audits or reviews. Trust, but verify.

Can open-source software contain malware?

Open-source software can contain malware, just like any other software. Malicious code can enter a project through compromised accounts, harmful contributions, or unofficial downloads. Using trusted sources and checking a project’s security history can help reduce the risk.

Are all open-source projects safe?

Not all open-source projects are safe. Some are well maintained and regularly reviewed, while others may be abandoned, poorly maintained, or contain vulnerabilities. Check a project’s activity, maintainers, security record, and dependencies before using it.

Is open-source software more secure than proprietary products?

No, open-source software is not automatically more secure than proprietary software. Granted, since its code can be inspected by anyone, it can make it easier for researchers to find and fix flaws. However, security still depends on active maintenance, updates, and careful use. A project with poor upkeep can still be risky.

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