Next.js 15.3.3 represents a minor update over the previous stable version, 15.3.2, focusing primarily on internal dependency updates and refinements rather than introducing significant new features for developers. Both versions share an identical core set of dependencies, including key libraries like busboy, postcss, @next/env, and styled-jsx, crucial for building robust React applications. The developer tooling and testing frameworks also remain consistent, with packages like webpack, storybook, jest, and @playwright/test present in both versions, ensuring a familiar development experience.
Developers considering upgrading should note only subtle differences, largely within the @next/swc ecosystem, where internal components like @next/swc-darwin-x64, @next/swc-linux-x64-gnu and others have been bumped to 15.3.3 to match the main package version. These changes often involve performance improvements and bug fixes within the Rust-based compiler and transformation pipeline. The optional dependencies also reflect this pattern, with version bumps to their respective 15.3.3 version. Furthermore, the releaseDate field shows the new version came out significantly later than the previous one: 2025-05-29T19:14:18.847Z, compared to 2025-05-06T22:31:01.870Z.
For developers already using Next.js 15.3.2, upgrading to 15.3.3 is likely a safe and recommended step to benefit from the latest bug fixes and performance enhancements within the core compiler toolchain and optional dependencies.
All the vulnerabilities related to the version 15.3.3 of the package
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
