Next.js has released version 14.2.8, a minor update following 14.2.7, continuing its evolution as a leading React framework. Both versions share core dependencies like busboy, postcss, @next/env, styled-jsx, and graceful-fs, ensuring a consistent foundation. The primary changes reside within the @next/swc version, aligning with the overall Next.js version in each release, and minor version adjustments in internal modules such as @next/polyfill-module, @next/polyfill-nomodule, and @next/react-refresh-utils.
For developers, the upgrade from 14.2.7 to 14.2.8 primarily brings refinements and potentially bug fixes within Next.js's core functionalities facilitated by the updated @next/swc compiler. While the extensive list of devDependencies remains largely the same, indicating a similar development environment, the updated internal modules suggest enhancements in areas like polyfilling and React Refresh, potentially improving browser compatibility and hot module replacement during development. The different file count and unpacked size signifies the scale of changes. Developers should test their applications after upgrading to ensure compatibility with any internal changes or bug fixes. Keep in mind that the peer dependencies like React and React DOM recommend the ^18.2.0 range in both versions.
All the vulnerabilities related to the version 14.2.8 of the package
Next.js Cache Poisoning
By sending a crafted HTTP request, it is possible to poison the cache of a non-dynamic server-side rendered route in the pages router (this does not affect the app router). When this crafted request is sent it could coerce Next.js to cache a route that is meant to not be cached and send a Cache-Control: s-maxage=1, stale-while-revalidate header which some upstream CDNs may cache as well.
To be potentially affected all of the following must apply:
pages/dashboard.tsx not pages/blog/[slug].tsxThe below configurations are unaffected:
This vulnerability was resolved in Next.js v13.5.7, v14.2.10, and later. We recommend upgrading regardless of whether you can reproduce the issue or not.
There are no official or recommended workarounds for this issue, we recommend that users patch to a safe version.
Next.js authorization bypass vulnerability
If a Next.js application is performing authorization in middleware based on pathname, it was possible for this authorization to be bypassed.
This issue was patched in Next.js 14.2.15 and later.
If your Next.js application is hosted on Vercel, this vulnerability has been automatically mitigated, regardless of Next.js version.
There are no official workarounds for this vulnerability.
We'd like to thank tyage (GMO CyberSecurity by IERAE) for responsible disclosure of this issue.
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