ZeroDay Findings
Sign inSign up

Findings

CVE-2026-29063

Immutable.js provides many Persistent Immutable data structures.

Published Mar 6, 2026 · corrected/updated Sep 10, 2026 · Red Hat immutable · evidence confidence high

A flaw was found in Immutable.js, a library for persistent immutable data structures. This vulnerability, known as Prototype Pollution, allows an attacker with low privileges to inject unwanted properties into core JavaScript object prototypes without user interaction. By manipulating specific APIs such as mergeDeep(), mergeDeepWith(), merge(), Map.toJS(), and Map.toObject(), a remote attacker could potentially execute arbitrary code or cause a denial of service (DoS).

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2026-29063 is a high public vulnerability record for Red Hat immutable. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether Red Hat immutable is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: immutable-js/immutable. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: CVSS 8.8. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-1321, CWE-915. Sources contributing to this record: csaf, csaf, cve_org, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.

  • Patch and remediation

    No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Mar 6, 2026 · NIST NVD

    Detected

    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.

  2. Sep 10, 2026 · NIST NVD

    Updated

    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

  • cpe immutable-js/immutableversion unspecified

Sources

  • CSAF AdvisoriesVendor advisoryRHSA-2026:9742:CVE-2026-29063

    A flaw was found in Immutable.js, a library for persistent immutable data structures. This vulnerability, known as Prototype Pollution, allows an attacker with low privileges to inject unwanted properties into core JavaScript object prototypes without user interaction. By manipul

    security.access.redhat.com
  • CSAF AdvisoriesVendor advisoryRHSA-2026:9848:CVE-2026-29063

    A flaw was found in Immutable.js, a library for persistent immutable data structures. This vulnerability, known as Prototype Pollution, allows an attacker with low privileges to inject unwanted properties into core JavaScript object prototypes without user interaction. By manipul

    security.access.redhat.com
  • CVE.orgVulnerability recordCVE-2026-29063

    Official CVE identifier

    cve.org
  • NIST NVDVulnerability recordCVE-2026-29063

    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

    nvd.nist.gov

References