{"cve":"CVE-2026-59880","nvd":{"published":"2026-07-08T16:16:34.517","modified":"2026-07-10T18:49:51.197","status":"Analyzed","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_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","score":8.7},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-407"],"references":["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/security/advisories/GHSA-xvcm-6775-5m9r"],"products":["immutable-js:immutable"],"source":"nvd","synced_at":"2026-10-19T22:42:16.820116992+00:00"},"epss":{"cve":"CVE-2026-59880","score":0.00665,"percentile":0.51809,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-xvcm-6775-5m9r","url":"https://osv.dev/vulnerability/GHSA-xvcm-6775-5m9r","summary":"Immutable: Hash-collision algorithmic complexity denial of service in Immutable.Map/Set","modified":"2026-09-10T03:51:12.758661308Z","packages":[{"ecosystem":"npm","name":"immutable","purl":"pkg:npm/immutable","ranges":[">=4.0.0-beta.1 <4.3.9"],"fixed":["4.3.9"]},{"ecosystem":"npm","name":"immutable","purl":"pkg:npm/immutable","ranges":[">=5.0.0-beta.1 <5.1.8"],"fixed":["5.1.8"]},{"ecosystem":"npm","name":"immutable","purl":"pkg:npm/immutable","ranges":["<3.8.4"],"fixed":["3.8.4"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}