CVE-2026-59880
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.66%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 4.0
- 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.66% probability · 50th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-407
- Affected
- immutable-js/immutable
- Source
- security-advisories@github.com
References
- https://github.com/immutable-js/immutable-js/commit/3dd7e5655012597a41873e328bf9142a8901527bPatch
- https://github.com/immutable-js/immutable-js/commit/e51d49fc612ded5ec4dfb94ff294d22074269b0fPatch
- 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-6775-5m9rExploit, Mitigation, Vendor Advisory
- https://github.com/immutable-js/immutable-js/security/advisories/GHSA-xvcm-6775-5m9rExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.