CVE-2026-29063CRITICAL 9.8EPSS p44.6%
CVE-2026-29063CVE-2026-29063
Description
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.
Scoring
| CVSS 3.1 | 9.8 (CRITICAL) |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 0.61% probability of exploitation · percentile 44.6% · 2026-06-19T12:03:05Z |
| Published | 2026-03-06 |
| Last modified | 2026-04-17 |
Underlying weaknesses· 1
References
1
| Type | Target | Confidence | Tier |
|---|---|---|---|
| Weakness | Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')cwe-1321 | 0% | live |
Related by meaning· 6
Nearest entities by semantic similarity across the cs-graph corpus.