Vulnerability library
Security checkJuly 21, 2026

Immutable.js `List` 32-bit trie overflow → unrecoverable DoS

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High severitynpmimmutable

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Description

List#set, List#setSize, List#setIn, List#updateIn (and the functional set / setIn / updateIn) mishandle an index or size in the range [2 ** 30, 2 ** 31):

  • On an empty List the operation enters an uncatchable infinite loop (a tight CPU spin; a surrounding try/catch never regains control).

Recommendation

Update the immutable package to the latest compatible version. Followings are version details:

  • Affected version(s): **>= 5.0.0-beta.1, < 5.1.8 < 4.3.9**
  • Patched version(s): **5.1.8 4.3.9**

References

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Related Issues

See something that needs correcting? Let us knowUpdated July 21, 2026