immutable-js Immutable.js up to 4.3.8/5.1.7 HashCollisionNode obj resource consumption

Summaryinfo

A vulnerability was found in immutable-js Immutable.js up to 4.3.8/5.1.7. It has been rated as problematic. The affected element is the function Immutable.Map/Immutable.fromJS/state.merge/mergeDeep of the file Immutable.js of the component HashCollisionNode. The manipulation of the argument obj leads to resource consumption. This vulnerability is listed as CVE-2026-59880. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in immutable-js Immutable.js up to 4.3.8/5.1.7 and classified as problematic. This issue affects the function Immutable.Map/Immutable.fromJS/state.merge/mergeDeep of the file Immutable.js of the component HashCollisionNode. The manipulation of the argument obj with an unknown input leads to a resource consumption vulnerability. Using CWE to declare the problem leads to CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. Impacted is availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-59880 since 07/07/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 4.3.9 or 5.1.8 eliminates this vulnerability.

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Productinfo

Type

• JavaScript Library

Vendor

• immutable-js

Name

• Immutable.js

Version

• 4.3.0
• 4.3.1
• 4.3.2
• 4.3.3
• 4.3.4
• 4.3.5
• 4.3.6
• 4.3.7
• 4.3.8
• 5.1.0
• 5.1.1
• 5.1.2
• 5.1.3
• 5.1.4
• 5.1.5
• 5.1.6
• 5.1.7

CPE 2.3info

• 🔒
• 🔒
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CPE 2.2info

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• 🔒

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Entryinfo

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