CVE-2026-29063

high

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.

References

https://github.com/immutable-js/immutable-js/security/advisories/GHSA-wf6x-7x77-mvgw

https://github.com/immutable-js/immutable-js/releases/tag/v5.1.5

https://github.com/immutable-js/immutable-js/releases/tag/v4.3.8

https://github.com/immutable-js/immutable-js/releases/tag/v3.8.3

Details

Source: Mitre, NVD

Published: 2026-03-06

Updated: 2026-03-06

Risk Information

CVSS v2

Base Score: 7.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

Severity: High

CVSS v3

Base Score: 9.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 8.7

Vector: 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

Severity: High

EPSS

EPSS: 0.00046