Next.js versions from 13.0.0 up to but excluding 15.5.28, and from 16.0.0 up to but excluding 16.4.1, contain a vulnerability where crafted requests targeting App Router applications with Server Actions can cause excessive CPU usage and block further request processing in the same process. Applications using the Pages Router or App Router without Server Actions are not affected. This issue is fixed in versions 15.5.28 and 16.4.1.
Vercel deepsec versions from 0.1.0 up to but not including 1.1.17 contain a link following vulnerability in the extractTarballLocally function. This flaw allows sandboxed code to write files outside its intended sandbox by planting symbolic or hard links in tarball results. An attacker controlling sandboxed code, such as a prompt-injected coding agent, can exploit this to write arbitrary files on the orchestrator host. The vulnerability has a CVSS 4.9 score, indicating medium severity.
Next.js versions from 15.0.0 up to but not including 15.5.27, and from 16.0.0 up to but not including 16.3.8, contain a vulnerability where a shared response cache key is insufficiently scoped. This allows an unauthenticated attacker to poison the cache via a crafted request, potentially causing cross-user content substitution or persistent denial of service until the cache entry is refreshed. The issue is fixed in versions 15.5.27 and 16.3.8.
Next.js is a React framework for building full-stack web applications. From 16.0.0 until 16.3.8, the `next dev` development server exposes a Model Context Protocol endpoint without reliably restricting cross-site requests. A malicious website visited by a developer can reach the endpoint and read the project's disk location, source code snippets from error reports, route inventory, and development logs. Production deployments do not serve this endpoint. This issue is fixed in version 16.3.8.
A Server-Side Request Forgery (SSRF) vulnerability exists in Next.js versions 16.0.0 through 16.3.7 in the Image Optimization feature when using images.remotePatterns. This allows attacker-controlled DNS resolution to bypass allow-list checks and fetch images from private IP addresses. Applications not using images.remotePatterns are not affected. The issue is fixed in version 16.3.8.
Next.js versions from 15.0.0 up to but not including 15.5.27, and from 16.0.0 up to but not including 16.3.8, contain a vulnerability where the response cache for statically generated or Incremental Static Regeneration pages using the Pages Router can be incorrectly keyed. This allows a request to replace one page's cached content with that of another route, causing incorrect content to be served to visitors until the cache is revalidated. Applications deployed on Vercel are not affected. The issue is fixed in versions 15.5.27 and 16.3.8.
CVE-2026-94544 is a medium severity vulnerability in Vercel's Next.js framework affecting versions >=16.3.0 and <16.3.8. It involves the use of a shared cache for pending `use cache` fills that does not distinguish between Draft Mode and regular requests. This can cause unpublished draft content to be served to unauthenticated users or published content to be served in draft previews. Additionally, if a regular request prerenders a page during this overlap, unpublished content may be persisted and served to all visitors until the page is revalidated.
Next.js is a React framework for building full-stack web applications. From 16.0.0 until 16.3.8, the next dev development server exposes a Model Context Protocol endpoint without reliably restricting cross-site requests. A malicious website visited by a developer can reach the endpoint and read the project's disk location, source code snippets from error reports, route inventory, and development logs. Production deployments do not serve this endpoint. This issue is fixed in version 16.3.8.
Next.js versions from 16.3.0 to 16.3.7 warm `use cache` handlers using `next/root-params` and can leak their return value to pages with different root params. With Cache Components enabled (cacheComponents: true), a 'use cache' function that calls another 'use cache' function that reads a root param can be keyed incorrectly when the inner call is served from an existing entry: the enclosing function's cache key then omits that root param. The enclosing entry is written once and reused for all root param values, so a response for one root param value can serve content produced for a different value — whether the page is prerendered at build time or at runtime, or rendered dynamically. Shared cache headers let downstream caches redistribute the content further.
What values are leaked cannot be attacker controlled. Which value's content is served depends only on which invocation wrote the entry first.
This has been patched in 16.3.8.
Satori is a library to convert HTML and CSS to SVG. Starting in version 0.0.27 and prior to version 0.33.5, Satori does not properly escape certain values before including them in generated SVG output. This can allow crafted values to be interpreted as SVG markup. The impact depends on how the generated SVG is consumed. Version 0.33.5 contains a patch. No complete workaround exists besides upgrading. Applications that cannot immediately upgrade should not render attacker-controlled content with Satori.
Next.js is a React framework for building full-stack web applications. From 13.4.0 until 15.5.24 and 16.3.3, Next.js applications using Pages Router or App Router without Cache Components on Windows-hosted servers do not consistently escape backslashes in route segments before constructing incremental-cache paths. In packages/next/src/shared/lib/router/utils/escape-path-delimiters.ts and packages/next/src/server/lib/incremental-cache/file-system-cache.ts, a remote request can supply encoded Windows path separators that traverse outside the intended cache root and expose private build data, including the server-reference-manifest encryption key. Disclosure of that key can enable remote code execution in the affected application. This issue is fixed in versions 15.5.24 and 16.3.3.
Next.js is a React framework for building full-stack web applications. In versions 13.0.0 through 15.5.20 and 16.0.0 through 16.2.10, crafted requests targeting Next.js applications using App Router with at least one Server Action can lead to excessive CPU usage blocking processing of further requests in the same process. This issue has been fixed in versions 15.5.21 and 16.2.11.
Next.js is a React framework for building full-stack web applications. In versions 16.0.0 through 16.2.10, crafted requests targeting Next.js applications using App Router built with Turbopack and a single entry in config.i18n.locales can bypass middleware/proxy based authentication. This issue has been fixed in version 16.2.11.
Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, Next.js applications using App Router, Server Actions (use server) or use cache endpoints can be disclosed bypassing any authentication on the pages where these endpoints are usually used. Server Action IDs can be disclosed to unauthenticated users via publicly served client artifacts (for example, static chunks containing action references). Affected users are applications using App Router and Server Actions. By itself, this disclosure is typically a recon/enumeration primitive; however, it can increase risk when combined with other weaknesses. This issue has been fixed in versions 15.5.21 and 16.2.11.
Next.js is a React framework for building full-stack web applications. In versions 15.5.0 through 15.5.20 and 16.0.0 through 16.2.10, when self-hosting Next.js with the default image loader, the Image Optimization API can optimize remotely hosted images if configured (not enabled by default). If those images contain malicious content, they can cause CPU exhaustion in /_next/image endpoints.Only config.images.remotePatterns is affected, and just the patterns in that array, whereas config.images.unoptimized: true, config.images.loader: 'custom', and Vercel are not impacted. This issue has been fixed in versions 15.5.21 and 16.2.11.
Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, a
rewrites() or redirects() rule that builds its external destination hostname from request-controlled input can be pointed at an arbitrary hostname, regardless of the rule's hostname suffix. For a rewrite, Next.js proxies the request to that arbitrary host and serves the response from the application's origin, leading to Server-Side Request forgery. A redirects() rule configured this way is vulnerable to an Open Redirect. This issue has been fixed in versions 15.5.21 and 16.2.11.
Next.js is a React framework for building full-stack web applications. In versions 13.0.0 through 15.5.20 and 16.0.0 through 16.2.10, requests targeting Next.js applications using App Router with at least one Server Action can lead to excessive memory consumption if that Server Actions uses the Edge runtime. This issue has been fixed in versions 15.5.21 and 16.2.11.
Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, a server-side fetch with a request body may return a cached response body from a different request to the same URL but different body. Confidential data in the POST's response body would then leak to unauthorized requests. Though the request itself will not be deduped. This is only an issue when receiving request bodies with a content type charset other than UTF-8. For example, the UTF-16 byte sequences for 삃삃 and 섄섄 in the request body would share the same cache. This issue has been fixed in versions 15.5.21 and 16.2.11.
Next.js is a React framework for building full-stack web applications. In versions 12.0.0 through 15.5.20 and 16.0.0 through 16.2.10, a server-side fetch with a request body may return a cached response body from a different request to the same URL but different body. Confidential data in the POST's response body would then leak to unauthorized requests. Though the request itself will not be deduped. This only applies to fetch calls with a request that has a different init than the one passed to fetch. A safe request would be: fetch(new Request(init), init). An unsafe request would be: fetch(new Request(init), aDifferentInit). This issue has been fixed in versions 15.5.21 and 16.2.11.
Next.js is a React framework for building full-stack web applications. In versions 14.1.1 through 15.5.20 and 16.0.0 through 16.2.10, when a Server Action forwards or redirects a request, an attacker can cause the server to send that outbound request to a malicious host (Server-Side Request Forgery). This requires the attacker's request to control Host-associated headers. In some configurations, it's also possible to obtain internal values that weaken middleware/proxy authorization. Applications that use Server Actions are affected when the incoming host header is not fixed to a trusted value. This typically occurs on custom servers, or on deployments not behind a proxy that pins the host. Managed hosting pins the host upstream and is not affected; next start and standalone output do the same from version 14.2 onward. This issue has been fixed in versions 15.5.21 and 16.2.11.