CVE•Published 2026-03-06•Modified 2026-09-10•1 article on news•6 live references•NVD data

CVE-2026-29063Immutable-js · Immutable

Vulnerability data via NVD (ingested)

CVSS v3.1

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS percentile

Exploit Prediction Scoring System · top 40% of all CVEs

Weaknesses (CWE)

CWE-1321Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')CWE-915Improperly Controlled Modification of Dynamically-Determined Object Attributes

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.

Timeline

Published 2026-03-06

Modified 2026-09-10

External references

NVD MITRE Exploit-DB GitHub PoC trickest/cve VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-29063

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Immutable-js Immutable"

All exposed Immutable-js Immutable instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Immutable"

HTTP body or banner mentions "Immutable" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-29063