Next.js 15.2.3 represents a minor iteration over the preceding 15.2.2, primarily focused on internal refinements and bug fixes to enhance stability and performance. While the core framework structure remains consistent, subtle adjustments within dependencies and optional dependencies reflect ongoing efforts to optimize the developer experience.
Notably, both versions share a vast landscape of dependencies, encompassing essential tools like postcss, styled-jsx, and @swc/* packages for styling and compilation needs. The devDependencies reveal an extensive suite of testing, building and utility libraries, including webpack, babel, typescript, and storybook, highlighting the robust ecosystem supporting Next.js development.
The key difference lies in the minor version bump within @next/env, @next/swc, @next/font and @next/react-refresh-utils, aligning these packages with the main Next.js version. This suggests incremental improvements within environment variable handling, SWC (Speedy Web Compiler) integration, font optimization, and React Refresh functionality which will improve the developer experience. Moreover, the optional dependencies for platform-specific SWC builds have also been updated to the newest version. Users leveraging these features directly may observe subtle enhancements. Developers should generally upgrade to 15.2.3 for the latest bug fixes for a more stable experience. The update ensures optimal compatibility and leverages the most recent improvements, although the high-level feature set remains largely unchanged between versions. The increased unpackedSize and later releaseDate also indicate the changes.
All the vulnerabilities related to the version 15.2.3 of the package
Next.js may leak x-middleware-subrequest-id to external hosts
In the process of remediating CVE-2025-29927, we looked at other possible exploits of Middleware. We independently verified this low severity vulnerability in parallel with two reports from independent researchers.
Learn more here.
Thank you to Jinseo Kim kjsman and RyotaK (GMO Flatt Security Inc.) with takumi-san.ai for the responsible disclosure. These researchers were awarded as part of our bug bounty program.
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
