CVE-2026-29063 — Immutable.js: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in immutable
Immutable.js provides many Persistent Immutable data structures. Prior to versions 3.8.3, 4.3.7, and 5.1.5, Prototype Pollution is possible in immutable via the mergeDeep(), mer…
Published: 2026-03-06 · CVSS: 8.7 · CVSS 4.0
Immutable.js provides many Persistent Immutable data structures. Prior to versions 3.8.3, 4.3.7, and 5.1.5, Prototype Pollution is possible in immutable via the mergeDeep(), mergeDeepWith(), merge(), Map.toJS(), and Map.toObject() APIs. This issue has been patched in versions 3.8.3, 4.3.7, and 5.1.5.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7