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Deserialization of Untrusted Data

CVE-2025-66478

High
10/10

Summary

A critical vulnerability (CVE-2025-55182) affects the Next.js framework because it depends on React Server Component transport packages that contain a flaw in how server-generated data is processed and delivered to the client. As a result, all stable Next.js 15.x and 16.x releases--and canary builds starting from 14.3.0-canary.77--may incorrectly handle RSC payloads, creating a risk of exposing or misprocessing server data within applications using the App Router. Although the issue originates in React, Next.js inherits it through its dependency chain, making the Next.js package ecosystem vulnerable as well. The problem is resolved in patched Next.js versions 15.0.5, 15.1.9, 15.2.6, 15.3.6, 15.4.8, 15.5.7, and 16.0.7, and all affected users should upgrade immediately--or downgrade canary to the latest stable 14.x release.

  • LOW
  • NETWORK
  • HIGH
  • CHANGED
  • NONE
  • NONE
  • HIGH
  • HIGH

CWE-502 - Deserialization of Untrusted Data

Deserialization of untrusted data vulnerabilities enable an attacker to replace or manipulate a serialized object, replacing it with malicious data. When the object is deserialized at the victim's end the malicious data is able to compromise the victim’s system. The exploit can be devastating, its impact may range from privilege escalation, broken access control, or denial of service attacks to allowing unauthorized access to the application's internal code and logic which can compromise the entire system.

References

Advisory Timeline

  • Published