high7.5
CVE-2026-59880
Immutable: Hash-collision algorithmic complexity denial of service in Immutable.Map/Set
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | immutable | >= 5.0.0-beta.1, < 5.1.8 | 5.1.8 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Immutable-Js | Immutable | before 4.3.9 from 5.0.0 before 5.1.8 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-xvcm-6775-5m9r
- https://github.com/immutable-js/immutable-js/security/advisories/GHSA-xvcm-6775-5m9r
- https://nvd.nist.gov/vuln/detail/CVE-2026-59880
- https://github.com/immutable-js/immutable-js/commit/3dd7e5655012597a41873e328bf9142a8901527b
- https://github.com/immutable-js/immutable-js/commit/e51d49fc612ded5ec4dfb94ff294d22074269b0f
- https://github.com/immutable-js/immutable-js/releases/tag/v4.3.9
- https://github.com/immutable-js/immutable-js/releases/tag/v5.1.8
- https://github.com/immutable-js/immutable-js/releases/tag/v3.8.4