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Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in immutable

CVE-2026-29063

  • immutable
High
8.7/10

Summary

Immutable.js provides many Persistent Immutable data structures. 3.x prior to versions 3.8.3, 4.x prior to versions 4.3.7, and 5.x prior to versions 5.1.5, Prototype Pollution is possible in immutable via the "mergeDeep()", "mergeDeepWith()", "merge()", "Map.toJS()", and "Map.toObject()" APIs. This issue has been patched in versions 3.8.3, 4.3.7, and 5.1.5.

  • LOW
  • NETWORK
  • NONE
  • NONE

CWE-1321 - Prototype Pollution

Prototype pollution is one of the lesser-known vulnerabilities. It allows attackers to abuse the rules of JavaScript by injecting properties into the general object “Object” in JS. Modifying the prototype of “Object” affects the behavior of all objects in the entire app, potentially resulting in denial of service, arbitrary code execution, cross-site scripting, etc.

References

Advisory Timeline

  • Published