Introduction – Why This Matters

If you’ve ever used a fast, modern website, there’s a good chance it was built with Next.js. Next.js is a popular tool for creating websites and especially web apps. Recently, a serious security issue surfaced in Next.js, identified as CVE-2025-29927.

At White Mountain Codeworks, we often use Next.js for client work. That’s why, the moment we heard about this flaw, we made sure our clients’ sites were secure.

A “House” Analogy

Picture your home, locked up tight with a sturdy, locked front door (strong passwords, good login security).

But imagine there’s a tiny basement window in the back that no one noticed was open. It’s not easy to reach, but it’s there. That’s what this vulnerability (CVE-2025-29927) was like. Even with a solid front door, someone could sneak in through that little-known opening and steal whatever they could find.

The Official Fix – Patch That Window!

The Next.js team and Vercel reacted quickly, rolling out an update to lock down this “basement window.” This fix is available in the latest Next.js release (13.5.2+). Even so, to stay safe, anyone running older versions should upgrade as soon as possible.

How White Mountain Codeworks is Handling It

• Scanning and Auditing: Each client's website was examined to see if it was running a potentially vulnerable version of Next.js. Luckily, WMC projects all keep to the newest, most secure versions of Next.js which do not include this exploit.
• Transparent Communication: We notified affected clients about the steps we took and why.
• Extra Security Checks: Beyond this fix, we revisited our standard security measures like validating user input and minimizing any publicly accessible routes.

What You Can Do (Even If You’re Not Technical)

• Keep Everything Updated: Ask your developer to stay on top of updates. This is important whether they (or you) are using Next.js, WordPress, or any other web development tool.
• Use Strong Passwords: A vulnerability in Next.js won’t matter if someone can guess your easy password.
• Monitor for Odd Behavior: Watch out for strange login attempts or changes to your website that you or your developer didn’t make.

Conclusion – Closing the Door for Good

No matter how advanced a tool is, vulnerabilities can (and do) appear.

The good news? The Next.js team moved fast, and at White Mountain Codeworks, we’ve taken all necessary steps to protect our clients’ sites.

If you have questions about how secure your Next.js application is, or if you’re ready for an expert team to build you something rock-solid and secure, reach out to us for a free consultation any time.

We’re here to help your business climb its mountain, safely.