CVE-2026-59879

HIGHCVSS 7.5/10EPSS 0.30%

Last modified

CVE-2026-59879 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Immutable.js provides many Persistent Immutable data structures. Prior to 4.3.9 and 5.1.8, List#set, List#setSize, List#setIn, List#updateIn, and the functional set, setIn, and updateIn mishandle an index or size in the range 2 ** 30 to 2 ** 31 in setListBounds in src/List.js, causing an empty List to enter an uncatchable infinite loop, a populated List to allocate without bound until process abort, or setSize to silently wrap large values. EPSS estimates a 0.30% chance of exploitation in the next 30 days.

Description

Immutable.js provides many Persistent Immutable data structures. Prior to 4.3.9 and 5.1.8, List#set, List#setSize, List#setIn, List#updateIn, and the functional set, setIn, and updateIn mishandle an index or size in the range 2 ** 30 to 2 ** 31 in setListBounds in src/List.js, causing an empty List to enter an uncatchable infinite loop, a populated List to allocate without bound until process abort, or setSize to silently wrap large values. This issue is fixed in versions 4.3.9 and 5.1.8.

Metrics

Weakness Enumeration

Affected Software

VendorProductVersions
Immutable-JsImmutable< 4.3.9
Immutable-JsImmutable>= 5.0.0, < 5.1.8

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-59879?
Immutable.js provides many Persistent Immutable data structures. Prior to 4.3.9 and 5.1.8, List#set, List#setSize, List#setIn, List#updateIn, and the functional set, setIn, and updateIn mishandle an index or size in the range 2 ** 30 to 2 ** 31 in setListBounds in src/List.js, causing an empty List to enter an uncatchable infinite loop, a populated List to allocate without bound until process abort, or setSize to silently wrap large values. This issue is fixed in versions 4.3.9 and 5.1.8.
How severe is CVE-2026-59879?
CVE-2026-59879 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.30% probability of exploitation in the next 30 days.
How do I fix CVE-2026-59879?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

Are you affected by CVE-2026-59879?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST