Next.js 15.1.8 represents a minor version update following 15.1.7, focusing on refinements and bug fixes rather than introducing groundbreaking new features. Examining the package.json diff reveals subtle shifts in internal dependencies and tooling. Core dependencies like @next/env, @next/swc, and @next/font have been bumped to 15.1.8, ensuring internal consistency within the Next.js ecosystem.
Notable changes also appear within the optional dependencies; the different versions of @next/swc for specific platforms (Darwin, Linux, Windows) reflecting a fine-tuning of the underlying SWC compiler integration. While the high-level APIs remain largely unchanged, developers can expect a more polished experience with potential performance gains from compiler optimizations and dependency upgrades.
For developers, this means a smoother upgrade process with minimal breaking changes. It's crucial to update to 15.1.8 to benefit from these fixes and ensure compatibility within the Next.js ecosystem. The increase in file count in this newer version suggests bug fixing and potentially some configuration enhancements, but it requires a deeper dive into the changelog for a definitive analysis. While both list the same peer dependencies, it's highly recommended to check for compatibility notes if you're using specific peer dependencies to avoid unexpected behaviours after the update.
All the vulnerabilities related to the version 15.1.8 of the package
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.
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.
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