CVE
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(), 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.
Package Versions Affected
Package Version
patch Availability
No items found.
Automatically patch vulnerabilities without upgrading
Fix Without Upgrading
Detect compatible fix
Apply safe remediation
Fix with a single pull request
CVSS Version
Severity
Base Score
CVSS Version
Score Vector
C
H
U
8.7
-
4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
C
H
U
0
-
C
H
U
7.5
-
3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Related Resources
No items found.
References
https://github.com/immutable-js/immutable-js/releases/tag/v3.8.3, 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/CVEProject/cvelistV5/tree/main/cves/2026/29xxx/CVE-2026-29063.json, https://github.com/immutable-js/immutable-js/security/advisories/GHSA-wf6x-7x77-mvgw, https://nvd.nist.gov/vuln/detail/CVE-2026-29063
Basic Information
Ecosystem
