CVE-2025-59472

A denial of service vulnerability exists in Next.js versions with Partial Prerendering (PPR) enabled when running in minimal mode. The PPR resume endpoint accepts unauthenticated POST requests with the Next-Resume: 1 header and processes attacker-controlled postponed state data. Two closely related vulnerabilities allow an attacker to crash the server process through memory exhaustion:

1. Unbounded request body buffering: The server buffers the entire POST request body into memory using Buffer.concat() without enforcing any size limit, allowing arbitrarily large payloads to exhaust available memory.

2. Unbounded decompression (zipbomb): The resume data cache is decompressed using inflateSync() without limiting the decompressed output size. A small compressed payload can expand to hundreds of megabytes or gigabytes, causing memory exhaustion.

Both attack vectors result in a fatal V8 out-of-memory error (FATAL ERROR: Reached heap limit Allocation failed - JavaScript heap out of memory) causing the Node.js process to terminate. The zipbomb variant is particularly dangerous as it can bypass reverse proxy request size limits while still causing large memory allocation on the server.

To be affected, an application must run with experimental.ppr: true or cacheComponents: true configured along with the NEXT_PRIVATE_MINIMAL_MODE=1 environment variable.

Strongly consider upgrading to 15.6.0-canary.61 or 16.1.5 to reduce risk and prevent availability issues in Next applications.

Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.

CVE-2025-59472 has a CVSS score of 5.9 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (16.1.5, 15.6.0-canary.61); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2025-59472? CVE-2025-59472 is a medium-severity uncontrolled resource consumption vulnerability in next (npm), affecting versions >= 16.0.0-beta.0, < 16.1.5. It is fixed in 16.1.5, 15.6.0-canary.61. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
2. How severe is CVE-2025-59472? CVE-2025-59472 has a CVSS score of 5.9 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of next are affected by CVE-2025-59472? next (npm) versions >= 16.0.0-beta.0, < 16.1.5 is affected.
4. Is there a fix for CVE-2025-59472? Yes. CVE-2025-59472 is fixed in 16.1.5, 15.6.0-canary.61. Upgrade to this version or later.
5. Is CVE-2025-59472 exploitable, and should I be worried? Whether CVE-2025-59472 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-59472 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-59472?
   • Upgrade next to 16.1.5 or later
   • Upgrade next to 15.6.0-canary.61 or later