CVE-2026-29063
March 06, 2026
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.
Affected Packages
https://github.com/immutable-js/immutable-js.git (GITHUB):
Affected version(s) >=v3.8.0 <v3.8.3Fix Suggestion:
Update to version v3.8.3https://github.com/immutable-js/immutable-js.git (GITHUB):
Affected version(s) >=v4.0.0-rc.1 <v4.3.7Fix Suggestion:
Update to version v4.3.7https://github.com/immutable-js/immutable-js.git (GITHUB):
Affected version(s) >=v5.0.0-beta.1 <v5.1.5Fix Suggestion:
Update to version v5.1.5immutable (NPM):
Affected version(s) >=4.0.0-rc.1 <4.3.8Fix Suggestion:
Update to version 4.3.8immutable (NPM):
Affected version(s) >=5.0.0 <5.1.5Fix Suggestion:
Update to version 5.1.5immutable (NPM):
Affected version(s) >=0.8.0-SNAPSHOT <3.8.3Fix Suggestion:
Update to version 3.8.3Related Resources (10)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
EPSS
Base Score:
0.05
