Posts tagged "Next-js"

We are aware of recently disclosed vulnerabilities affecting Next.js applications:

1. CVE-2025-55173: Next.js Image Optimization – Arbitrary File Download
2. CVE-2025-57822: Next.js Middleware – SSRF via Misuse of next()
3. CVE-2025-57752: Next.js Image Optimization – Cache Poisoning / Unauthorized Disclosure

As a security precaution, we recommend upgrading to the latest versions of Next.js and enabling automatic updates of the OpenNext Netlify Next.js adapter.

The engineering team at Netlify has reviewed these and determined the following impact on Netlify sites: *

1. CVE-2025-55173: Next.js Image Optimization – Arbitrary File Download

Sites on Netlify are not vulnerable.

Next.js sites on Netlify use Netlify’s Image CDN instead of the affected built-in Next.js Image Optimization feature. Furthermore, Netlify Image CDN strips Content-Disposition headers, which is required for successful exploitation of this vulnerability. With this header removed it is not possible to force a file download or override the filename, even in case of a mismatch between the requested image type and the source file type.

2. CVE-2025-57822: Next.js Middleware – SSRF via Misuse of next()

Sites on Netlify are not vulnerable.

Our OpenNext adapter uses Edge Functions to run middleware and relies on the context.next() API as the underlying implementation of NextResponse.next() calls, passing the original request URL and preventing this attack vector.

3. CVE-2025-57752: Next.js Image Optimization – Cache Poisoning / Unauthorized Disclosure

Next.js sites on Netlify are potentially vulnerable, if the sites use the next/image component to fetch images from a source that uses headers to conditionally serve images.

Next.js sites using the next/image component will automatically opt into Netlify’s Image CDN which, by design, will automatically cache the source assets on Netlify’s Edge Cache. This means that a source image that is served behind an authorization header will get cached on the Netlify Edge Cache in order to improve performance. Upgrading to the newest version of Next.js will not change this behavior.

If your Next.js site serves images from a protected source, we advise you to not use the next/image component so that you have full control over the caching and authorization strategies required for your use-case.

We are working continually with the Next.js team and are committed to making your sites secure on Netlify.

The Next.js team recently disclosed CVE-2025-32421, a low-severity vulnerability allowing for CDN cache poisoning in some scenarios.

The engineering team at Netlify has confirmed that all Next.js sites on Netlify are not vulnerable. The vulnerability requires use of a CDN that may cache responses without explicit Cache-Control headers, but Netlify’s CDN never does so.

As a general security precaution, we recommend upgrading to the latest versions of the Next.js framework and allowing automatic updates of the OpenNext Netlify Next.js adapter.