Vulnerability Description
Immutable.js provides many Persistent Immutable data structures. Prior to 4.3.9 and 5.1.8, Immutable.Map and Immutable.Set keep keys that share the same 32-bit hash in a HashCollisionNode collision bucket that is scanned linearly, allowing an attacker who controls keys inserted into a Map, such as through Immutable.Map(obj), Immutable.fromJS(obj), state.merge(userObject), or mergeDeep, to craft many colliding keys and degrade insertion and lookup to consume disproportionate CPU. This issue is fixed in versions 4.3.9 and 5.1.8.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Immutable-Js | Immutable | < 4.3.9 |
Related Weaknesses (CWE)
References
- https://github.com/immutable-js/immutable-js/commit/3dd7e5655012597a41873e328bf9Patch
- https://github.com/immutable-js/immutable-js/commit/e51d49fc612ded5ec4dfb94ff294Patch
- https://github.com/immutable-js/immutable-js/releases/tag/v4.3.9Release Notes
- https://github.com/immutable-js/immutable-js/releases/tag/v5.1.8Release Notes
- https://github.com/immutable-js/immutable-js/security/advisories/GHSA-xvcm-6775-ExploitMitigationVendor Advisory
- https://github.com/immutable-js/immutable-js/security/advisories/GHSA-xvcm-6775-ExploitMitigationVendor Advisory
FAQ
What is CVE-2026-59880?
CVE-2026-59880 is a vulnerability with a CVSS score of 7.5 (HIGH). Immutable.js provides many Persistent Immutable data structures. Prior to 4.3.9 and 5.1.8, Immutable.Map and Immutable.Set keep keys that share the same 32-bit hash in a HashCollisionNode collision bu...
How severe is CVE-2026-59880?
CVE-2026-59880 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-59880?
Check the references section above for vendor advisories and patch information. Affected products include: Immutable-Js Immutable.