Vulnerability DatabaseCVE-2026-29063
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CVE-2026-29063
Published:March 06, 2026
Updated:April 26, 2026
Immutable.js provides many Persistent Immutable data structures. Prior to versions 3.8.3, 4.3.8, 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, 4.3.8, and 5.1.5.
Affected Packages
immutable (CDN_JS):
Affected version(s) >=5.0.0 <5.1.5
Fix Suggestion:
Update to version 5.1.5
immutable (CDN_JS):
Affected version(s) >=2.0.0 <3.8.3
Fix Suggestion:
Update to version 3.8.3
immutable (CDN_JS):
Affected version(s) >=4.0.0 <4.3.8
Fix Suggestion:
Update to version 4.3.8
https://github.com/immutable-js/immutable-js.git (GITHUB):
Affected version(s) >=v4.0.0-rc.1 <v4.3.8
Fix Suggestion:
Update to version v4.3.8
https://github.com/immutable-js/immutable-js.git (GITHUB):
Affected version(s) >=v5.0.0-beta.1 <v5.1.5
Fix Suggestion:
Update to version v5.1.5
https://github.com/immutable-js/immutable-js.git (GITHUB):
Affected version(s) >=v3.8.0 <v3.8.3
Fix Suggestion:
Update to version v3.8.3
immutable (NPM):
Affected version(s) >=5.0.0 <5.1.5
Fix Suggestion:
Update to version 5.1.5
immutable (NPM):
Affected version(s) >=4.0.0-rc.1 <4.3.8
Fix Suggestion:
Update to version 4.3.8
immutable (NPM):
Affected version(s) >=0.8.0-SNAPSHOT <3.8.3
Fix Suggestion:
Update to version 3.8.3
Additional Notes
The description of this vulnerability differs from MITRE.
Related Resources (10)
https://nvd.nist.gov/vuln/detail/CVE-2026-29063
https://github.com/immutable-js/immutable-js/commit/16b3313fdf2c5f579f10799e22869f6909abf945
https://github.com/immutable-js/immutable-js/issues/2178
https://github.com/immutable-js/immutable-js/releases/tag/v4.3.8
https://github.com/immutable-js/immutable-js/releases/tag/v5.1.5
https://github.com/immutable-js/immutable-js/commit/6ed4eb626906df788b08019061b292b90bc718cb
https://github.com/immutable-js/immutable-js
https://github.com/immutable-js/immutable-js/security/advisories/GHSA-wf6x-7x77-mvgw
https://github.com/immutable-js/immutable-js/commit/6e2cf1cfe6137e72dfa48fc2cfa8f4d399d113f9
https://github.com/immutable-js/immutable-js/releases/tag/v3.8.3
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CVSS 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')
CWE-1321
EPSS
Base Score:
0.21