Infinite Loop Vulnerability in Immutable.js Affecting List Data Structures
CVE-2026-59879

8.7HIGH

Key Information:

Vendor

Immutable-js

Status
Immutable-js
Vendor
CVE Published:
8 July 2026

What is CVE-2026-59879?

A vulnerability in Immutable.js affects List functions including set, setSize, setIn, and updateIn. Specifically, these functions mishandle index or size values within a particular range, leading to an uncatchable infinite loop for empty Lists or unbounded memory allocation for populated Lists. This issue arises in specific versions prior to 4.3.9 and 5.1.8 and can cause significant performance degradation or even process aborts. Users are advised to update to the patched versions to mitigate these risks.

Affected Version(s)

immutable-js >= 5.0.0-beta.1, < 5.1.8 < 5.0.0-beta.1, 5.1.8

immutable-js < 4.3.9 < 4.3.9

References

https://github.com/immutable-js/immutable-js/security/adv...
x_refsource_CONFIRM
https://github.com/immutable-js/immutable-js/commit/a1a1e...
x_refsource_MISC
https://github.com/immutable-js/immutable-js/commit/f0bc9...
x_refsource_MISC

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.