Next.js version 14.2.16 represents a minor update focusing on refinements and stability compared to its predecessor, 14.2.15. While the core description remains consistent - "The React Framework" - careful examination reveals subtle yet impactful changes beneficial to developers.
The dependencies field is almost identical, indicating that core functionality remains largely unchanged. However, the @next/env and @next/swc dependencies are bumped to version 14.2.16 meaning that part of the update has been some changes or bug fixing in the build tools used by next.js.
Looking at optionalDependencies, the @next/swc binaries for various platforms (darwin, linux, win32, x64, arm64, gnu, musl, msvc, ia32) have also been updated to 14.2.16, suggesting potential performance enhancements or bug fixes within the Rust-based compiler. This is the most critical difference for developers as SWC handles much of the compilation process.
The devDependencies section, crucial for development workflows, shows no apparent version changes and the only visible change is the unpackedSize parameter inside the dist section, from 86261612 to 86273228. This value suggests that some internal changes may have occurred but without any impact in the dependencies.
The releaseDate shifting from October 8th to October 23rd reflects approximately two weeks of development, bug fixing, and testing between the versions. Developers considering an upgrade should review the official Next.js changelog for a comprehensive list of specific fixes and enhancements included in this release. This incremental update typically translates to a more polished and reliable experience for building performant React applications.
All the vulnerabilities related to the version 14.2.16 of the package
Next.js Allows a Denial of Service (DoS) with Server Actions
A Denial of Service (DoS) attack allows attackers to construct requests that leaves requests to Server Actions hanging until the hosting provider cancels the function execution.
Note: Next.js server is idle during that time and only keeps the connection open. CPU and memory footprint are low during that time.
Deployments without any protection against long running Server Action invocations are especially vulnerable. Hosting providers like Vercel or Netlify set a default maximum duration on function execution to reduce the risk of excessive billing.
This is the same issue as if the incoming HTTP request has an invalid Content-Length header or never closes. If the host has no other mitigations to those then this vulnerability is novel.
This vulnerability affects only Next.js deployments using Server Actions.
This vulnerability was resolved in Next.js 14.2.21, 15.1.2, and 13.5.8. We recommend that users upgrade to a safe version.
There are no official workarounds for this vulnerability.
Thanks to the PackDraw team for responsibly disclosing this vulnerability.
Next.js Race Condition to Cache Poisoning
Summary
We received a responsible disclosure from Allam Rachid (zhero) for a low-severity race-condition vulnerability in Next.js. This issue only affects the Pages Router under certain misconfigurations, causing normal endpoints to serve pageProps data instead of standard HTML.
Credit
Thank you to Allam Rachid (zhero) for the responsible disclosure. This research was rewarded as part of our bug bounty program.
Authorization Bypass in Next.js Middleware
It is possible to bypass authorization checks within a Next.js application, if the authorization check occurs in middleware.
15.2.314.2.2513.5.912.3.5Note: Next.js deployments hosted on Vercel are automatically protected against this vulnerability.
If patching to a safe version is infeasible, it is recommend that you prevent external user requests which contain the x-middleware-subrequest header from reaching your Next.js application.
Information exposure in Next.js dev server due to lack of origin verification
A low-severity vulnerability in Next.js has been fixed in version 15.2.2. This issue may have allowed limited source code exposure when the dev server was running with the App Router enabled. The vulnerability only affects local development environments and requires the user to visit a malicious webpage while npm run dev is active.
Because the mitigation is potentially a breaking change for some development setups, to opt-in to the fix, you must configure allowedDevOrigins in your next config after upgrading to a patched version. Learn more.
Learn more: https://vercel.com/changelog/cve-2025-48068
Thanks to sapphi-red and Radman Siddiki for responsibly disclosing this issue.
Next.js Affected by Cache Key Confusion for Image Optimization API Routes
A vulnerability in Next.js Image Optimization has been fixed in v15.4.5 and v14.2.31. When images returned from API routes vary based on request headers (such as Cookie or Authorization), these responses could be incorrectly cached and served to unauthorized users due to a cache key confusion bug.
All users are encouraged to upgrade if they use API routes to serve images that depend on request headers and have image optimization enabled.
More details at Vercel Changelog
Next.js Content Injection Vulnerability for Image Optimization
A vulnerability in Next.js Image Optimization has been fixed in v15.4.5 and v14.2.31. The issue allowed attacker-controlled external image sources to trigger file downloads with arbitrary content and filenames under specific configurations. This behavior could be abused for phishing or malicious file delivery.
All users relying on images.domains or images.remotePatterns are encouraged to upgrade and verify that external image sources are strictly validated.
More details at Vercel Changelog
Next.js Improper Middleware Redirect Handling Leads to SSRF
A vulnerability in Next.js Middleware has been fixed in v14.2.32 and v15.4.7. The issue occurred when request headers were directly passed into NextResponse.next(). In self-hosted applications, this could allow Server-Side Request Forgery (SSRF) if certain sensitive headers from the incoming request were reflected back into the response.
All users implementing custom middleware logic in self-hosted environments are strongly encouraged to upgrade and verify correct usage of the next() function.
More details at Vercel Changelog