CVE-2026-59880 – Immutable.js: Hash-collision algorithmic complexity denial of service in Immutable.Map/Set

CVE ID :CVE-2026-59880

Published : July 8, 2026, 3:44 p.m. | 4 minutes ago

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.

Severity: 0.0 | NA

Visit the link for more details, such as CVSS details, affected products, timeline, and more…